HomeMy WebLinkAboutWater Supply and Distribution Plan Sept 1998CITY OF OAK PARK HEIGHTS
Water Supply And Distribution Plan
Oak Park Heights, Minnesota
September, 1998
File No. 55 -98 -801
Table of Contents
TABLE OF CONTENTS
LISTOF FIGURES ......................................................................... ............................... ............................III
LIST OF T
EXECUTIVE SUMMARY
INTRODUCTION ............................ ...............................
GROWTH AND WATER DEMAND .. ...............................
EXISTING FACILITIES ................... ...............................
ULTIMATE STUDY AREA WATER SYSTEM ..................
ECONOMIC ANALYSIS .................. ...............................
RECOMMENDATIONS ................... ...............................
.............................. ............................... 1
.............................. ............................... I
.............................. ............................... I
........................ ............................... 2
......................... ............................... 2
......................................... ............................... 3
INTRODUCTION
WATER SYSTEM POLICY .........................
BACKGROUND ......... ...............................
OBJECTI VES ............. ...............................
WATERDEMAND..._ .................................................................................................. .................._...........9
GENERAL...................................................................................................................... ...............................
9
LAND USE AND IMPACT ON THE LOCAL COMPREHENSIVE PLAN .................................. ...............................
9
POPULATION............................................................................................................... ...............................
11
VARIATIONSIN WATER USAGE .................................................................................. ...............................
14
WATER DEMAND BY CUSTOMER CATEGORY ............................................................. ...............................
20
LARGE VOLUME CUSTOMERS ..................................................................................... ...............................
23
PROJECTED WATER USAGE ........................................................................................ ...............................
23
CONSERVATION.......................................................................................................... ...............................
26
FIREDEMAND ............................................................................................................ ...............................
26
PHASINGOF SYSTEM .................................................................................................. ...............................
27
EXISTING FACILITIES ............................................................................................ ............................... 28
WATER SUPPLY..........
Existing Wells........
Well Water Quality
WATER TREATMENT.
STORAGE ......... ...............................
DISTRIBUTION SYSTEM ..................
Hydraulic Analysis ....................
ADEQUACY OF EXISTING FACR.ITIE
PROPOSED FACILITIES
SUPPLY - STORAGE CONSIDERATIONS
HYDRAULIC ANALYSIS .....................
RAW WATER SUPPLY .......................
WellsRequired ..................................................................................... ...............................
Wellhead Protection and Groundwater Exploration ........................... ...............................
28
28
28
28
29
30
30
32
9
35
36
37
37
38
Water Supply and Distribution Plan
WATERTREATMENT ..................................................................................................
............................... 38
STORAGE ....................................................................................................................
............................... 39
General ..................................................................................................................
............................... 39
FutureWater Storage Facilities ............................................................................
............................... 39
DISTRIBUTIONSYSTEM ..............................................................................................
............................... 40
General ..................................................................................................................
............................... 40
HydraulicAnalysis ................................................................................................
............................... 40
WATERSYSTEM PHASING ..........................................................................................
............................... 42
ECONOMIC ANALYSIS
45
COSTESTIMATES ........................................................................................................
............................... 45
CAPITAL IMPROVEMENT PROGRAM ............................................................................
............................... 46
WATERCHARGES .......................................................................................................
............................... 47
AREACHARGES ..........................................................................................................
............................... 48
CONNECTIONCHARGES ..............................................................................................
............................... 50
COMPARISON TO EXISTING CONNECTION CHARGE ....................................................
............................... 50
APPENDIX A — MODEL INPUT
52
APPENDIX B — PRESSURES AND ELEVATIONS ............................................... ............................... 53
APPENDIX C — COST ESTIMATES ........................................................................ ............................... 54
APPENDIX D — WATER QUALITY REQUIREMENTS ...................................... ............................... 55
APPENDIX E — WATER EMERGENCY PLAN ..................................................... ............................... 56
APPENDIX F — WATER CONSERVATION PLAN ............................................... ............................... 57
Water Supply and Distribution Plan ii
List of Figures
FIGURE I - LOCATION MAP .................................... ...............................
FIGURE 2 - LAND USE MAP .................................... ...............................
FIGURE 3 - POPULATION PROTECTIONS ..............................
FIGURE 4 A- ANNUAL PUMPING RECORDS ........................
FIGURE 4 B- PUMPAGE RECORDS ....... ...............................
FIGURE 5 - WATER USE BY CUSTOMER CATEGORY ...............................
FIGURE 6. MAXIMUM DAY DEMAND CURVE ........... ...............................
.............. ...............................
6
..................... I.....................
10
............... ...............................
13
............... ...............................
16
............... ...............................
19
............... ...............................
22
............... ...............................
36
Water Supply and Distribution Plan iii
List of Tables
TABLE 1.
LAND USE TYPE DESCRIPTIONS .....................................................................
............................... 11
TABLE 2.
POPULATION PROJECTIONS ............................................................................
............................... 12
TABLE 4.
WATER CONNECTION SUMMARY .....................................................................
............................. 20
TABLE 5.
WATER USAGE BY CUSTOMER CATEGORY ....................................................
............................... 21
TABLE 6.
TOP TEN WATER USERS 1998 FIRST QUARTER (MG) ...................................
............................... 23
TABLE7.
FUTURE DEMANDS .........................................................................................
............................... 25
TABLE 8
- PROJECTED WATER USE ..............................................................................
............................... 26
TABLE9.
DESIGN FIRE FLows ......................................................................................
............................... 27
TABLE l0
EXISTING STORAGE FACILITIES ...................................................................
............................... 29
TABLE11.
Flow TEST RESULTS ...................................................................................
............................... 31
TABLE 12.
AREAS WITH Low FIRE FL ow5 ....................................................................
............................... 33
TABLE 13.
WELLS REQUIRED ........................................................................................
............................... 38
TABLE 14.
ULTENATE STORAGE FACILITIES ..................................................................
............................... 40
TABLE 15.
AREAS BELow DESIGN FIRE FLOWS ............................................................
............................... 42
TABLE 16.
SUPPLY /STORAGE PHASING ..........................................................................
............................... 44
TABLE 17.
WATER SYSTEM COST SUMMARY ................................................................
............................... 45
TABLE 18.
WATER SYSTEM CAPITAL IMPROVEMENT PROGRAM ...................................
............................... 47
TABLE 19
- LATERAL BENEFIT ESTIMATE .....................................................................
............................... 48
TABLE 20.
AREA CHARGE REQUIREMENTS ...................................................................
............................... 49
TABLE 21.
ESTIMATED NUMBER OF CONNECTIONS .......................................................
............................... 50
TABLE 22.
CONNECTION CHARGE REQUIREMENTS .......................................................
............................... 50
Water Supply and Distribution Plan iv
Executive Summary
Introduction
This report represents a Comprehensive Water Supply and Distribution Plan of a water
system, which will meet both the near -term and ultimate needs of the City of Oak Park
Heights.
Growth and Water Demand
Oak Park Heights population was been steadily increasing to the current served
population of 3,900. The City does not anticipate a significant change in this trend, and
expects their served population to grow to 7,500 people by the year 2020. Oak Park
Heights currently pumps 550,000 gallons of water on an average day and pumps 1.4
million gallons of water on a peak day.
Water use has increased steadily as population has grown. In 1997, Oak Park Heights
pumped an average of 550,000 gallons per day. The maximum day occurred in 1997
with 1.4 million gallons being pumped on one day. The projected maximum day water
demand for the ultimate land use is estimated to be 5.30 MGD
Existing Facilities
The existing water supply and distribution system has served Oak Park Heights' needs
quite well. The City presently obtains its raw water from 2 wells with a combined
capacity of 2.4 MGD. The City's firm capacity with the largest well out of service is
1.15 MGD.
Water Supply and Distribution Plan
Two elevated storage facilities stabilize pressure during peak water demands and also
serve as a source of water during fires or power outages. There is a total existing storage
volume of 750,000 gallons.
Ultimate Study Area Water System
The study area system shown on Figure 7 consists of the following:
• 4 new Jordan Aquifer wells.
• Expansion of the existing water distribution system.
• One new ground storage tank and booster station with a total capacity of
2.0 million gallons.
Economic Analysis
The improvement program for Oak Park Heights at ultimate trunk water supply, storage
and distribution system is estimated at $9,044,000 as shown in the Capital Improvement
Plan on Table 18. The ultimate cost is broken down into supply, treatment, storage, and
distribution as follows.
Component
Cost
Supply
$ 2,800,000
Storage
$ 1,080,000
Distribution
$ 5,164,000
Total
$9,044,000
The ultimate water system will be completely paid for by future development. The
following sources of revenue pay for the improvements.
Lateral Benefit
$ 1,020,000
Area Charge
5,114,000
Connection Charge
2,910,000
Total Revenue
$9,044,000
Water Supply and Distribution Plan 2
The City should review the Capital Improvement Program annually and modify the
program to better serve community development needs. The entire water supply and
distribution plan should be revised every five to seven years.
Recommendations
Based upon the results and analysis of this study, the following are recommendations for
the City of Oak Park Heights and Oak Park Heights City Council:
1. Initiate the feasibility study for Well 3.
2. Expedite acquisition of sites for wells, booster station, storage facilities,
and any easements required to connect these sites to the water system and
to prevent conflicts with surrounding development.
3. Monitor water quality and consumer complaints to screen out problems
with high iron and manganese concentrations and insure compliance with
drinking water quality standards.
4. Annually review the Capital Improvements Program and water charge
system to better serve community development needs.
5. The entire water supply and distribution plan should be revised every five
to seven years.
6. Revise the City's existing lateral benefit, connection and area charge
system in accordance with the improvements recommended in this report.
The recommended minimum charges are as follows:
Lateral Benefit
Residential 6 inch
Commercial/Industrial 12 inch
Area Charge $3,760/ Acre
Connection Charge $465 1 REU
Water Supply and Distribution Plan 3
Continue preparing a wellhead protection plan in accordance with rules.
Begin hydrogeologic reconnaissance to determine the feasibility of the
well field.
Water Supply and Distribution Plan
Introduction
Water System Policy
The policy of the Oak Park Heights water supply system is to provide the consumers with
safe, high quality, and affordable drinking water. The system will provide this vital
service while assuring the long -term protection of our supply from contamination and
excessive depletion.
The development of a water system capable of supplying and distributing potable water
of high quality to all points of demand at acceptable residual pressures requires advanced
planning. Such a system is dependent upon a strong network of trunk water mains
complemented by properly sized and strategically located supply and storage facilities.
A comprehensive plan based on the most reliable information presently available is
necessary to ensure that adequate facilities are provided during a significant growth
period and to allow flexibility for future adjustments. Without proper planning,
haphazard and piece -meal construction can result in either undersized or over -sized
facilities.
Background
The purpose of this water supply and distribution plan is to provide a comprehensive
improvement program of water needs for the City of Oak Park Heights.
The City of Oak Park Heights is located in the Twin Cities Metropolitan area of
Minnesota in Washington County, as shown in Figure 1.
A municipal water system can be divided into three main categories:
• Supply and Treatment Facilities
• Storage Facilities
Water Supply and Distribution Plan 5
LOCATION MAP
OAK PARK HEIGHTS, MINNESOTA FIGURE 1
WATER SUPPLY AND DISTRIBUTION PLAN
Bonestroo
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OAK PARK HEIGHTS, MINNESOTA FIGURE 1
WATER SUPPLY AND DISTRIBUTION PLAN
Bonestroo
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OEM Anderlik &
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Engineers & Architects
• Distribution System
Supply and Treatment Facilities include all equipment necessary to pump, treat, and
distribute the amounts of water demanded by the system. For Oak Park Heights, it is
proposed to consider only groundwater supply sources, although this does not preclude
the possibility of using surface water supply at some future date, or water from some
other outside sources. The supply facilities thus include the wells, pump houses,
controls, water treatment facilities, raw water transmission mains, and all related
facilities.
The Storage Facilities are the reservoirs used throughout the system to store water for
usage during emergency and peak conditions. Water from storage is fed into the system
by gravity or by pumping from a booster station. Two types of reservoirs feed water
directly into the system by gravity. These include a ground reservoir with the floor
resting on the ground (typically on a hill or other high point) or an elevated reservoir with
columns supporting the tank. A ground reservoir may also be constructed at an elevation,
which requires a booster station to pump the water into the system at the proper pressure.
The Distribution System consists of the trunk water mains (primarily 10 inches or larger
in diameter), the lateral water mains (4 to 8 inches in diameter), the service pipes, valves,
hydrants, and all appurtenances necessary to convey water from the supply sources and
reservoirs to the points of demand. Since the water laterals are normally routed along
residential streets within a development, it is impossible to predict with any degree of
accuracy where future laterals will be placed in undeveloped areas. These lines are
excluded from consideration in analyzing the trunk distribution system hydraulics.
The phased construction of the Oak Park Heights water distribution system has primarily
been dependent on development within the City. Where development occurs, water
mains are constructed to serve those specific developments. However, development
within the City is not always absolutely contiguous and gaps in the distribution system
may result. As development continues to move farther away from the supply wells and
reservoirs, these gaps can cause problems with insufficient supply and pressures since
they prevent the 'looping" of the distribution system.
Looping of the distribution system provides system reliability in the event of a water
main break, but more importantly it provides the large flows required for fighting fires.
Water Supply and Distribution Plan 7
One of the purposes of this report is to evaluate potential water pressure and supply
problems and determine the most feasible solutions
Objectives
The primary objective of this report is to develop a water system plan for the City of Oak
Park Heights based on the most recent land use planning available. Specifically, the
following objectives are outlined:
1. Determine the water demands expected within the City and the production
capacity and storage required to meet these demands.
2. Develop a trunk water main system in accordance with present planning.
3. Determine near -term supply and storage needs in order to allow sufficient lead -
time for the addition of facilities to the system.
4. Hydraulically analyze the proposed ultimate system to ensure adequate residual
pressures, and to develop an economical and energy - efficient ultimate water system.
5. Develop preliminary cost estimates for supply, storage and distribution to form a
basis for a satisfactory financing program.
Water Supply and Distribution Plan 8
Water Demand
General
Capacity requirements for the three water system components of supply, storage and
distribution are dictated by the demands placed upon them for production and
distribution. The design of the water supply and distribution system for Oak Park
Heights was based on estimates of the future water demands. Phasing of the system
improvements was based on estimates of near -term needs.
Water demand (both peak and average) is affected by many factors including population,
population distribution, commercial and industrial activity, water quality, water rates,
climate, soil conditions, economic level of the community, sewer availability, water
pressures, and the condition of the water system. The most important factor is land
usage, which encompasses population and non - residential use activity. Projections of
near -term and ultimate study area land usage and population for Oak Park Heights were
correlated with past and present water demands to develop estimates of both near -term
and saturation water demands in the City.
Land Use and Impact on the Local Comprehensive Plan
The Water Supply and Distribution Plan was based on the Comprehensive Plan for the
City. The City Land Use Plan for Oak Park Heights that served as a basis for the
development of the proposed water supply and distribution system is presented in Figure
2. Oak Park Heights' staff developed preliminary land use assumptions for the ultimate
study area land use in the City. The land use assumptions beyond the approved Land Use
Plan were conceptual in nature for the needs of this study. It is understood that if these
land use assumptions are altered in future years, the sizing requirements derived in this
report must be revised.
Water Supply and Distribution Plan 9
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In order to estimate water demands, the City's Land Use Plan was used to divide the City
into the land use types, which are defined in Table 1. The acreage for each land use type
was measured in gross developable acreage — that is the total acreage reduced by minor
undevelopable areas. The gross developable acres include small parks and street rights -
of -way.
Table 1. Land Use Type Descriptions
Land Use Types
Descriptions
Single Family Residential
Single family residential development at a
density range of 0 -4 dwelling units per
acre.
Multiple Family Residential
Residential development at more than 8
dwelling units per acre.
Commercial
Includes limited business, retail sales and
service, general business, and public
offices.
Industrial
Includes general manufacturing, industrial,
and
warehousing facilities.
Government/Institutional
Includes elementary, secondary and post
secondary leaming institutions.
Manufactured Housing Park
Single family residential development at a
density range of more than 8 dwelling
units per acre.
Park/Open Space
Includes parks and restricted open areas.
Population
Saturation population estimates for the City of Oak Park Heights for the study area were
developed for use in the design of the distribution system, storage facilities, and well
fields. Population projections for the City are listed and shown graphically on Figure 3.
The population data in Table 2 and Figure 3 is based on Census figures, City estimates,
and the Ultimate population was determined by regression of the estimated populations.
The City's planned residential densities were used to project total population in the Study
Area. The facilities described in this report are designed to serve a population of 13,700.
Actual growth rates will affect only the timing of construction and not the actual design
of the system.
Water Supply and Distribution Plan I I
At this time, the City has no intent of providing water service to areas outside the MUSA
or City Limits. As the MUSA and City Limits expand by orderly annexation, the water
system will be expanded.
Table 2. Population Projections
Water Supply and Distribution Plan 12
Metropolitan Council Projections
City Projections
Year
Blueprint
Employment
Served
Population
1997
NA
NA
3,900
1998
NA
NA
4,000
1999
NA
NA
4,500
2000
3,900
3,100
5,000
2005
NA
NA
5,500
2010
5,150
4,150
6,000
2020
6,500
4,500
7,500
2045
NA
NA
13,700
Water Supply and Distribution Plan 12
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Variations in Water Usage
The rate of water consumption will vary over a wide range during different periods of the
year and during different hours of the day. Several characteristic demand periods are
recognized as being critical factors in the design and operation of a water system. The
demand rates are expressed in million gallons per day (MGD) which, in the case of a
daily demand, indicates the total amount of water pumped in a 24 -hour period. Hourly
rates are also expressed in million gallons per day. In the case of an hourly rate, the rate
in MGD is determined by assuming that the pumpage would continue at the indicated rate
for 24 hours.
The average day demand is equal to the total annual pumpage divided by the number of
days in the year. The principal significance of the average day demand is as an aid in
estimating maximum day and maximum hour demands. The average day demand is also
utilized in estimating future revenues and operating costs such as power and chemical
requirements, since these items are determined primarily by the total annual water
requirements rather than by daily or hourly rates of usage. Pumping records, which were
used in determining average daily demands, are presented in Table 3 and are also shown
graphically on Table 4 A.
Water Supply and Distribution Plan 14
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The maximum day demand is the critical figure in the design of certain elements of the
waterworks system. The principal items affected by the maximum day demands are:
• supply of available water,
• raw water supply facilities, and
• treatment plant capacity, and
• treated water storage requirements.
The raw water supply facilities must be adequate to supply water near the maximum day
demand rate. Sufficient treated water storage should be provided to meet hourly demands
in excess of the water supply capacity. The installed capacities should also include
reserves for growth, industrial development and fire protection.
The maximum demands upon the water system are encountered during short periods of
time, usually on days of maximum consumption. These short period demands are
referred to as hourly demands, and they seldom extend over a period of more than three
or four hours, generally during hot summer evenings when the sprinkling load is the
highest.
The demand variations for the maximum day, maximum month, and minimum month
for the past ten years are shown in Table 3. The monthly pumpages for the City are
shown graphically on Figure 4 Bfor the past ten years. The maximum demand periods
were established after a thorough examination of daily pumping records. The average
day demand is also shown in the Table 3, expressed in million gallons per day. The mean
value for the maximum day shown in Table 3 can be used for any projected water
demand computations in future studies.
The maximum hour consumption rates impose critical demands on the distribution
system, and major elements of the waterworks facilities must be designed to meet these
demands and provide satisfactory service at all times.
Maximum hour demands in Oak Park Heights are currently supplied through water drawn
from storage towers on the distribution system. Although the rate of consumption is high
during periods of maximum hourly demand, the duration of the extreme rate is relatively
short. Therefore, a moderate quantity of water withdrawn from storage towers
strategically located on the system assures satisfactory service, minimizes the total
maximum hour pumping and transmission main capacity required, and permits more
Water Supply and Distribution Plan 17
uniform and economical operation of the pumping facilities. Storage on the system is
also an important factor in insuring reliability of service during emergencies resulting
from power failure, temporary outages of water supply facilities, and from sudden and
unusual demands brought about by fires or line breaks.
The storage tank is refilled during the night and early morning hours when demand on the
system is low. A strong network of piping is needed between the supply point and
reservoirs to insure that a sufficient amount of water can reach the storage tanks during
the refilling period to provide the required supply for the following day.
Water Supply and Distribution Plan 18
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Water Demand by Customer Category
The City has been keeping track of water pumping records and has broken their water use
into four main categories of water users, residential, institutional/commercial, and
industrial. Table 4 shows the number of connections by customer category for the years
1988 to 1997. Table 4 shows the total use and percentage of use by customer category
and unaccounted for water use (water pumped less water sold).
Table 4. Water Connection Summary
(1) 1994 numbers are estimated
(2) Institutional were combined with commercial
In 1997, there were an estimated 1,049 connections to the water system; 938 of those
connections were residential.
From 1988 - 1997, residential connections grew by approximately 50% from 640
connections to 938 connections. About 89 % of the total connections to the water system
Water Supply and Distribution Plan 20
Number of Connections
Year
Residential
Institutional
Commercial
Industrial
1988
741
8
77
0
1989
776
8
88
0
1990
794
8
88
0
1991
828
6
92
0
1992
857
6
97
0
1993
888
9
100
0
1994(1)
906
9
104
0
1995(2)
943
-
106
0
1996 (2)
932
114
0
1997(2)
938
111
0
(1) 1994 numbers are estimated
(2) Institutional were combined with commercial
In 1997, there were an estimated 1,049 connections to the water system; 938 of those
connections were residential.
From 1988 - 1997, residential connections grew by approximately 50% from 640
connections to 938 connections. About 89 % of the total connections to the water system
Water Supply and Distribution Plan 20
were residential, yet, the residential water use is approximately 49% of the total water
use, as shown on Table 5. Table 5 and Figure 5 summarize water usage by customer
category and percentage of total water used.
Table 5. Water Usage by Customer Category
Year
Res.
(MG)
% of
Total Use
(Res.)
Comm/
Instit.
(MG)
% of
Total
Use
(Comm/
Instit)
Unacct.
(MG)
% of
Total
Use
( Unacct)
Total
(MG)
19891
91.776
58.51%
57.041
36.37%
8.037
5.12 %
156.854
1990
76.814
49.46%
55.785
35.91%
22.717
14.63%
155.316
19911
85.784
52.65%
57.123
35.06%
20.032
12.29%
162.939
1992
99.831
56.55%
59.554
33.73%
17.160
9.72%
176.545
19931
86.165
51.54%
68.371
40.89%
12.650
7.57%
167.186
1994
94.110
50.73%
73.087
39.39%
18.327
9.88%
185.524
19951
94.176
49.43 %
65.971
34.62%
30.383
15.95%
190.530
1996
99.701
60.85%
64.087
39.12%
0.049
0.03%
163.837
19971
98.474
49.43%
65.491
32.87%
35.259
17.70%
199.224
Avg.
91.9
53.1%
62.9
36.3 %
18.3
10.6%
173.1
(1) Institutional and commercial use are combined
The unaccounted for water use has stayed fairly stable, with an overall system average of
10.6% from 1989 - 1997. The "unaccounted" category in Table 5 and Figure 5 pertains
to water used for flushing existing water mains and new street projects, fighting fires, city
sprinkling and use and unaccounted for water due to water main leaks, breaks, meter
inaccuracies, etc. American Water Work Association (AWWA) recommends that water
systems maintain a 10% or less unaccounted for water use. Oak Park Height will
continue to make moves to improve the distribution system and respond efficiently to
leaks in order to reduce unaccounted for water below 10 %.
Water Supply and Distribution Plan 21
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Large Volume Customers
The records of the top ten water users for the City are identified in Table 6. The two
large volume customers in Oak Park Heights are Minnesota Correctional Facility and
Washington County.
Table 6. Top Ten Water Users 1998 First Quarter (MG)
Customer
Quarter
Beginning
3/31/98
Washington County
3.745
MN Correctional Facility
3.532
Sunnyside Marina
2.895
ISD #834
1.616
Sunnyside Apartments
1.082
St. Croix Car Wash
1.024
Menards
0.918
St. Croix Cleaners
0.839
R.J. Estates
0.755
Oak Park Association
0.715
Projected Water Usage
Estimated future water usage is based on population, land use, and water use trends.
Peak demands vary with land use. High peak usage rates are experienced in low- density
areas during hot, dry periods due to extensive lawn sprinkling, while usage in high -
density areas depends on human consumption to a greater extent. Average daily usage
for commercial and industrial areas is very high, but is much more stable than residential
Water Supply and Distribution Plan 23
usage. Therefore, although commercial and industrial areas have high average usage, the
peak usage (maximum day and maximum hour demands) is comparable to those in
residential areas. Demand rate variations during the day are shown in Figure 6.
Each of the land use categories in Table 1 was examined with consideration given to
population density, area to be sprinkled and other activities likely to occur compatible
with projected land usage. Demand rates were then developed for each land use type.
The resulting rates, which were used in analyzing Oak Park Heights' water system are
presented in Table 7.
Water Supply and Distribution Plan 24
Table 7. Future Demands
Total water usage for designated discrete points of demand on the water system was
determined for the purpose of hydraulic analysis and system design. This was
accomplished by dividing the Study Area into subareas whose total demand was assumed
to be located at a designated point in each subarea. The subareas were then further
subdivided into the various land use categories, based on the land use map. By applying
the unit demand rates from Table 7, the total demand for each subarea was developed.
The point demand rates for the Oak Park Heights' water system are presented in
Appendix A. The point designations in Appendix A refer to points on Figure 7 at the
back of this report.
Water Supply and Distribution Plan 25
Densities
Demand Rates (GPM/Ac.)
Land Use
Units
Person
Person
Demand
Average
Maximum
Peak
Type
/acre
/Unit
/Acre
Day
Day
Hour
Low
3.2
3.2
10.2
90 gcd
0.64
1.91
3.82
Density
Medium
5
2.5
12.5
80 gcd
0.69
1.94
3.88
Density
High
12
2
24.0
70 gcd
1.17
2.8
5.6
Density
Comm.
-
1800
1.25
1.87
3.74
GPD /ac.
Industrial
-
1800
1.25
1.87
3.74
District
GPD /ac.
Mixed
1800
1.25
1.87
3.74
GPD /ac.
Instit.
1800
1.25
1.87
3.74
GPD /ac.
Total water usage for designated discrete points of demand on the water system was
determined for the purpose of hydraulic analysis and system design. This was
accomplished by dividing the Study Area into subareas whose total demand was assumed
to be located at a designated point in each subarea. The subareas were then further
subdivided into the various land use categories, based on the land use map. By applying
the unit demand rates from Table 7, the total demand for each subarea was developed.
The point demand rates for the Oak Park Heights' water system are presented in
Appendix A. The point designations in Appendix A refer to points on Figure 7 at the
back of this report.
Water Supply and Distribution Plan 25
Anticipated maximum day water demands are presented in Table 8. The maximum day
water demands are used for the sizing of supply and potential treatment facilities. A
record of actual maximum and average day demands should be charted to aid in the
sizing and phasing of future facilities.
Table 8 - Projected Water Use
Year
Population
Maximum Day
Demand (MGD)
Demand
(gpm)
1997
3,900
1.40
972
1998
4,000
1.49
1,035
1999
4,500
4.68
1,170
2000
5,000
1.86
1,290
2005
5,500
2.05
1,420
2010
6,000
2.24
1,560
2020
7,500
2.80
1,940
Ultimate 2,043
13,700
5.30
3680
Conservation
The effect of conservation on future water use patterns is uncertain. The normally
expected increase in domestic water consumption associated with improved economic
conditions, greater use of water consuming household appliances, and improved sanitary
facilities is expected to be curtailed by water conservation measures such as sprinkling
bans, education, rate increases, and new plumbing fixture designs. A complete
discussion on conservation is included in the City's Water Emergency and Conservation
Plan.
Fire Demand
Water usage for fire demand is also a vital consideration in the design of a water supply
and distribution system. Fire demand varies greatly from normal usage in that an
extremely large quantity of water is required from a single demand point in a very short
Water Supply and Distribution Plan 26
time. The quantity of water used for fires is almost negligible when compared to other
annual usage categories, but because of the extreme rate of usage during an emergency
situation, fire demands frequently govern design.
The Insurance Services Office (ISO) recommends that a system the size of Little Falls's
be capable of delivering a fire demand of 500 gpm to 6,500 gpm for varying duration's
depending on the rate of demand. However, ISO doesn't provide premium deductions
for providing fire demands over 3,500 gpm. Recent experience with many commercial
and industrial users has shown that 2,000 gpm to 3,500 gpm is usually a sufficient flow
rate to operate their sprinkler systems. Residential areas require a flow rate of 500 gpm
to 1,000 gpm dependent upon the housing spacing. Available fire flows were checked at
various locations in the system for both the existing system and the saturation design
system. ISO flow data summary taken in May of 1996 has been included in the
Appendix.
The fire flows that were used in the design of the Oak Park Heights' water system are
shown in Table 9.
Table 9. Design Fire Flows
Land Use
Required Fire Flow(gpm)
Duration(hrs)
Commercial\lndustrial
3,500
3
InstitutionahPublic
3,500
3
Residential
1,000
2
Phasing of System
For the purpose of phasing additions to the system, water demands for each year were
determined by multiplying the demand rates in Table 7 by the appropriate acres of each
land type expected to develop by that year. The resulting projected demand rates are
shown in Table 8.
Water Supply and Distribution Plan 27
Existing Facilities
Water Supply
Existing Wells
The City of Oak Park Heights primarily utilizes two production wells having a total
capacity of approximately 1700 gpm. Both wells draw water from the Jordan aquifer.
The firm capacity is defined as the capacity with the largest well out of service. Oak Park
Heights' firm well capacity is 800 gpm (1.15 MGD).
Well Water Quality
The U.S. Environmental Protection Agency (EPA) has established national drinking
water standards. These standards contain federally enforceable maximum contaminate
level (MCL) standards for substances known to be hazardous to public health.
Water quality parameters are defined and regulated by two sets of standards - Primary
and Secondary. Primary Standards are set for those substances known to be a hazard to
public health. Secondary Standards are set for those substances that, although not
hazardous to public health, frequently cause drinking water to have objectionable
aesthetic qualities, such as taste and odor. A complete discussion of the drinking water
standards can be found in Appendix D.
The water quality for the wells show low levels of iron and manganese. The water is
generally hard (210 mg/1). In -home water softeners will remove hardness for residents
who desire softer water.
Water Treatment
The City of Oak Park Heights does not have a water treatment plant at this time. Fluoride
is added at the well pump houses and pumped directly into the distribution system. Both
Water Supply and Distribution Plan 28
wells are equipped with chlorination feed systems, however these systems are not in use
at this time.
Storage
Maximum hour demands are supplied through a combination of water from the supply
facilities and water drawn from storage reservoirs on the water distribution system.
Although the rate of consumption is high during periods of maximum hourly demand, the
duration of the extreme rate is relatively short. Therefore, a moderate quantity of water
withdrawn from storage reservoirs strategically located on the system assures satisfactory
service, minimizes the total maximum hour pumping and transmission main capacity
required, and permits more uniform and economical operation of the system and pumping
facilities.
Storage on the system is also an important factor in insuring reliability of service during
emergencies resulting from loss of power, temporary outages of water supply facilities,
and from sudden and unusual demands brought about by fire. The storage allows these
fluctuations in water demands to be met without having additional pumping capacity in
reserve which would be sitting idle most of the time.
Water from storage is fed into the system either by gravity or by pumping from a booster
station. Two types of reservoirs feed water into the system by gravity. These are
classified as either ground reservoirs with the floor resting on the ground or as elevated
reservoirs with columns supporting the tank. A ground reservoir may also be constructed
at an elevation that requires a booster station to pump water into the system.
The City of Oak Park Heights currently has 750,000 gallons of useable storage in the
system. A summary of these facilities is presented in Table 10.
Table 10 Existing Storage Facilities
High Water
Level
Reservoir
Type
Storage Volume
(Gal)
Year
Constructed
1084
Elevated
250,000
1967
1084
Elevated
500,000
1991
Water Supply and Distribution Plan 29
Distribution System
The existing distribution system consists of lines that vary in size from 4 inch to 12 inch
diameter. All mains are DIP or CIP. Static pressures readings range from 50 to 90
pounds per square inch (psi). throughout the system. The City has not had any reported
problems with low or high pressure areas in the distribution system.
Because the City's topography varies so much, the water system operates on three
pressure zones. Pressure reducing valves serve the lower elevation areas of the city and
keep static pressures at acceptable levels. The three pressure zones operate at the
following high levels:
Zone High Water Level
High Pressure Zone 1083.8
Intermediate Pressure Zone 1001.0
Low Pressure Zone 898.0
Hydraulic Analysis
Oak Park Heights' entire water supply and distribution system was modeled in detail
using a hydraulic computer model (known as Cybernet). The results of this model are
discussed in more detail in the next section. The first step in the process is to create a
computer model of the existing supply and distribution system. The purpose of this
model is to find any problems within the existing system and to serve as a foundation for
a model of the entire system (existing and future). It is important for the model of the
existing system to accurately portray how the existing system is functioning. This is
accomplished by hydrant flow testing of the existing system to calibrate the model.
Oak Park Heights' system was flow tested in eight different locations in the month of
July and August, 1998. The results of these flow tests are presented in Table 11. The
computer model is then run with the same conditions in an attempt to match the results.
After several trials in which model characteristics are adjusted, it is possible to match the
computed model results with the field test results. These results are shown in Table 11.
The test results matched well in all the tests, indicating that the computer model
accurately portrays Oak Park Heights' system.
Water Supply and Distribution Plan 30
Table 11. Flow Test Results
The following assumptions were made when calibrating the model:
• Possible closed pipe on Upper 61" (Paris Avenue to Paul Avenue) or Paul
Avenue (Upper 61" to 62 "
• Pipe on Upper 56" (Oren Avenue to Osgood Avenue) is 8 inch instead of 6
inch.
• PRV I not working properly during fire flows.
Water Supply and Distribution Plan 31
Location
Residual
Actual
Computer Model
Location
(node)
Pressure
Flow (gpm)
Residual Pressure
(psi)
(psi)
Newberry Ave/
Newberry Circle
16
52
1090
52
Upper 54 /Obrien
Ave
175
56
1130
58
.56 /56 Circle
325
63
1200
61
Oren Ave /Oren
Ave Cir
360
48
1090
47
Panaman/61"
1006
31
720
32
Peabody/Upper61"
1090
47
1020
46
Penrose/56' Ave.
2080
37
860
36
Sunnyside
Apartments (S.
Hydrant)
2012
49
1010
48
Upper 61 "/Paris
1065
29
710
28
The following assumptions were made when calibrating the model:
• Possible closed pipe on Upper 61" (Paris Avenue to Paul Avenue) or Paul
Avenue (Upper 61" to 62 "
• Pipe on Upper 56" (Oren Avenue to Osgood Avenue) is 8 inch instead of 6
inch.
• PRV I not working properly during fire flows.
Water Supply and Distribution Plan 31
Adequacy of Existing Facilities
The existing water supply and distribution system for the City of Oak Park Heights has
served the various water demands quite well. Scheduled improvements in the supply,
storage, and distribution facilities have proven to be cost - effective and timely. The
existing wells have met supply needs up to this point. The existing storage facilities
provide satisfactory static and residual pressures to most areas.
The existing distribution system also serves the City of Oak Park Heights' needs well. A
Cybernet computer model was built to identify areas that may need improvement in the
future. The model identified the following problem areas:
• Low Pressures: Junction 2110 was the only area with low (less than 40 psi) residual
pressures. This is primarily due to high ground elevations for the corresponding
pressure zone.
• High Pressures: Much of the City on the east side of Osgood Avenue North and
south of T.H. 36 has high pressure (greater than 90 psi) when the water towers are
rapidly filling. Although these pressures are fairly high, they are still considered
acceptable.
• Low Fire Flows: Some areas of the City are not able to meet the recommended fire
flows. Table 12 shows the areas with insufficient fire flows.
Water Supply and Distribution Plan 32
Table 12. Areas with Low Fire Flows
Junction
Area
Fire Flow
Required
(gpm)
Available
(gpm)
40
Northwest Commercial
3,500
3,030
85, 260, 265, 345, 350,
355 360,38 , 82,384,
385,386,390,1007
North Commercial and
Washington County
3,500
1,100 to
2,900
1000, 1005, 1006
Washington County*
3,500
860 to 990
1020, 1025, 1030, 1035
North Residential
1,000
800 to 910
290
MN Correctional Facility
3,500
1,700
295, 2055
South Dead Ends
3,500
500,900
* Note: Washington County has a separate fire service to the facility from the High
Pressure Zone. Limited additional fire protection (860 gpm to 990 gpm) is
available at the hydrants on Panama Ave.
• Supply: The City needs a back -up well to provide supply for the Maximum Day
Demand.
• Storage: The City does not have sufficient storage to fight a large fire on a peak day.
The following calculation (in gallons) shows the required storage to meet the fire
demand.
Maximum Day Demand (1998) 1,500,000
Fire Flow (3500 gpm for 3 hrs) 630,000
Total Water Required 2,130,000
Well Supply (800 gpm for 24 hrs) 1,200,000
Water From Storage 750,000
Total Water Supply 1,950,000
• Pressure Reducing Valves: Proper operation of the City's three pressure reducing
valves is essential. The City should establish a maintenance and testing program for
Water Supply and Distribution Plan 33
these valves. The Intermediate and Low Pressure Zones have no supply Source other
than these valves. If the valves fail to close, extremely high pressures will occur in
the lower elevation areas of the City.
Modifications proposed to strengthen the existing system are discussed in the following
section.
Water Supply and Distribution Plan 34
Proposed Facilities
Supply- Storage Considerations
Supply capacity, storage volume, and distribution system capacity are interrelated to a
great degree. Reservoirs act as additional supply sources during peak periods when the
primary supply source is incapable of meeting the demand. Thus, the storage tends to
stabilize the peaks in water demand and allows the system to produce water at a lower,
more uniform rate. The distribution system must be capable of carrying the flows from
both the supply source and reservoirs without allowing pressures to drop below
approximately 40 psi. Static pressure should be within a range of approximately 40 to 90
psi, if possible. The system must also be capable of conveying water from the source of
supply to the reservoirs for storage without allowing the development of high pumping
heads and high pressures in the system during low usage periods.
There are an infinite number of combinations of supply and storage that can be used to
meet peak water demands. The ideal combination is found where the sum of the cost of
all the facilities in the system reaches a minimum. A close approximation of this point
can be obtained by an analysis of supply and storage costs.
For the vast majority of communities, the ideal combination of supply and storage is
found when the supply equals 100% of the maximum day demand. Based on our analysis
and discussions with City Staff, we recommend that the City of Oak Park Heights'
system have the capacity to produce water at a rate equal to 100 % of the maximum day
demand.
The amount of storage required for Oak Park Heights' water system was found by
looking at the typical maximum day demand variation curve (shown in Figure 6) and at
fire flow demands. This curve should be checked with future peak days.
Water Supply and Distribution Plan 35
Figure 6. Maximum Day Demand Curve
250
200
m
E
m
p
T
p 150
E
E
m
100
O
C
U
U
a 50
Peak Demand
(2 times Maximum Day)
Demand Variation
Storage = 30 0 b of Max.
Day Demand
Maximum Day Demand
Supply = 100% of
Maximum Day Demand
[in
��acA\ • ti 9 h b 6 1 0 9 ' O N N NI, N3 , � -�- , y0 N ry0 2 X13' v'b c`Art
Time of Day
The shaded area above the maximum day demand line in Figure 6 represents 18% of the
maximum day total demand. This percentage takes into account hourly fluctuations and
will have to be provided by storage facilities. In addition to that, a safety factor is
required to account for fire flows, unusual demands on the system and operational
concerns. This safety factor was estimated to be 12% of the maximum day total demand,
and was based on a 3,500 gpm fire flow sustained for 3 hours and on actual operating
levels in the towers being 2 or 3 feet lower than the high water level. A total of 30% of
maximum day demand is required as a minimum for storage. Effective storage is
considered to be water available for use at an adequate residual pressure (not lower than
40 feet below the system high water level).
Hydraulic Analysis
The Oak Park Heights water system was analyzed in detail using the Cybernet hydraulic
computer model. The model describes the entire system, including high service pumps,
Water Supply and Distribution Plan 36
reservoirs, and distribution mains and analyzed the system for several static cases and
through a time simulation during the design maximum demand day.
The time simulation analysis examined the system on an hourly basis over the entire
maximum demand day, including peak demand periods, reservoir - filling conditions, and
critical pressures. The analysis used the maximum day demand curve presented on
Figure 6. A peak hourly demand of two times the maximum day demand is incorporated
into the curve.
Input for the computer model includes pipe sizes and lengths, point supplies and
demands, storage reservoir characteristics, pump performance curves, and ground
elevations. A summary of the input demands is presented in Appendix A. The model
then computes data for various times of the day based on the demand curve. The data
includes pipe flows and velocities, energy losses, pressures at each demand point,
pumping rates, and storage reservoir levels.
The Cybemet computer model runs inside of AutoCAD, a computer aided drafting and
design program. This allows the actual hydraulic analysis to be run in the graphical
environment of Figure 7 at the back of this report. Analysis of this data facilitates the
design of an economical and adequate water system. A summary of the output file is
presented in Appendix B. Results of this analysis and recommendations for
improvements are presented later in the report.
Raw Water Supply
Wells Required
As discussed previously, the most economical way to meet the demand conditions in Oak
Park Heights is to have a total well firm capacity equal to 100% of the maximum day.
For the Oak Park Heights study area, the required total firm production capacity is 3,680
gpm (5.30 MGD). Total firm capacity is defined as the capacity available with the
largest well out of service. Typically, firm capacity for systems with more than ten wells
is defined as the capacity with one out of every ten wells out of service. Peak demands
will be supplied by storage on the system.
Water Supply and Distribution Plan 37
Approximately 4 additional wells will be required to meet the total ultimate production
capacity of 5.30 MGD. Future wells will be added as necessary by increased demand.
Phasing of anticipated improvements is shown on Table 13. The estimated number of 4
future wells could be reduced or increased if the estimated study area population of
13,700 changes or the system is interconnected with cities. Future water use patterns and
conservation measures also will affect the number of wells required.
Table 13. Wells Required
Notes:
(1) Existing capacity with largest well out of service.
(2) Assumes future wells at 800 gpm.
Wellhead Protection and Groundwater Exploration
Water supply protection is an essential part of the Oak Park Heights water plan. The City
has started the wellhead protection planning process. The first phase of planning was
completed in February, 1998 with a report by Northern Environmental entitled, Wellhead
Protection Area And Drinking Water Supply Management Area Deliniations, And
Aquifer And Well Vulnerability Assessments.
Water Treatment
Some communities that utilize the Jordan aquifer build a treatment plant to remove iron
and manganese. At this time, iron and manganese removal is not necessary in Oak Park
Heights.
The City should begin disinfecting their water supply. This is commonly done at the
wells with chlorine gas.
Water Supply and Distribution Plan 38
WELLS
Required Capacity
3,680 gpm
Existing Firm Capacity
800 gpm
Additional Capacity Required
2,880 gpm
Additional Wells Required
4
Notes:
(1) Existing capacity with largest well out of service.
(2) Assumes future wells at 800 gpm.
Wellhead Protection and Groundwater Exploration
Water supply protection is an essential part of the Oak Park Heights water plan. The City
has started the wellhead protection planning process. The first phase of planning was
completed in February, 1998 with a report by Northern Environmental entitled, Wellhead
Protection Area And Drinking Water Supply Management Area Deliniations, And
Aquifer And Well Vulnerability Assessments.
Water Treatment
Some communities that utilize the Jordan aquifer build a treatment plant to remove iron
and manganese. At this time, iron and manganese removal is not necessary in Oak Park
Heights.
The City should begin disinfecting their water supply. This is commonly done at the
wells with chlorine gas.
Water Supply and Distribution Plan 38
Storage
General
The existing and proposed storage sites for the Oak Park Heights water distribution
system are shown on Figure 7. A total of 1.75 million gallons (MG) of effective storage
at three sites is planned. The most important considerations in the selection of the type
of storage facilities are safety, reliability and ease of operation. A gravity feed type of
storage facility, either elevated or ground, provides a safe and reliable source of water,
easy to operate, and allows for smooth operation of pump controls.
Elevated storage reservoirs consist of a tank supported above the ground by a tower. The
height of the tower depends on the high water level of the system and the ground
elevation of the construction site. The elevated tank is allowed to "ride" on the
distribution system with water flowing by gravity out of the tank when the pressure in the
system is low. The tank fills when the pressure in the distribution system is greater than
the water level in the tank. Elevated storage tanks are a safe source of water during
emergencies and power outages, since the water will flow by gravity to the point of
demand.
Surface storage reservoirs are located on the ground and sometimes require a booster
station to pump the water into the distribution system. A system of valves is required to
operate a reservoir of this type. Since the height of this reservoir is lower than the static
pressure in the distribution system, valves, which prevent water from entering the tank
when it is full, must be provided. For ease of operation, a surface reservoir of this type
should be located adjacent to an elevated reservoir. The pumps and valves in the booster
station are activated by changes in the level of water in the elevated tank. Since a surface
reservoir depends on pumps to boost water into the distribution system, standby pumps
are driven by some power source other than commercial electricity as a precaution
against a power failure.
Future Water Storage Facilities
Table 14 shows the existing and proposed storage facilities required to provide the
ultimate required storage capacity of 1.75 million gallons. The proposed locations for the
reservoirs are shown on Figure 7. The amount of storage required may be reduced or
increased depending on population, water usage patterns, and conservation measures.
Water Supply and Distribution Plan 39
Table 14. Ultimate Storage Facilities
Storage Site
Reservoir
High Water
Capacity(MG)
Usable
Type
Elevation
Capacity(MG)
West Side of
Elevated
1083.8
0.25
0.25
City Hall
Norell Ave
N15 81h Street N
Elevated
1083.8
0.50
0.50
New South of
Ground/
Prison
Booster
1001
2.00
1.00
Total Ultimate System Storage
2.75
1.75
(1) Existing Storage
(2) Usable storage is defined as the storage available while still maintaining
adequate residual pressures.
The proposed south storage facility consists of a 2.0 MG ground storage tank and a
booster pumping station. The ground storage tank will feed the Intermediate Pressure
Zone (High Water Level 1001) by gravity. Booster pumps will supply the High Pressure
Zone (High Water Level 1083.8) during peak hour demands.
Distribution System
General
The proposed ultimate distribution system for Oak Park Heights is presented on Figure 7
at the back of this report. The existing distribution system was discussed in the previous
section.
Hydraulic Analysis
Hydraulic analysis of the distribution system was performed by a Cybemet computer
program as described previously. The program computed flows and residual pressures
that were then analyzed to locate problem areas. Water main sizes, storage tank
Water Supply and Distribution Plan 40
characteristics, and pump controls were then revised and the program run again until the
problem was corrected. Ground elevations as well as static and residual hydraulic grade
lines and pressures are tabulated in Appendix B for points in the water system. These
hydraulic grade lines and pressures are based on operation during maximum hourly
demand or during the period after maximum hourly demand, whichever was lower.
The time simulation computer analysis was used to design and analyze the performance
of the saturated Study Area water system during the maximum day. The types of
alternatives that were tried during the several computer runs can be grouped into three
categories:
(1) Changes in size and location of the projected elevated tanks,
preserving the ultimate total storage.
(2) Changes in diameter of the proposed water mains.
(3) Addition of new water mains.
In looking at the different alternatives, the selected best possible option was a trade -off
among the following parameters:
a) Tank Operation: Including minimum level, ending level and total
operation time for each tank.
b) High Pressure Nodes: Identifying high - pressure nodes (above 90
psi) during low demand (tank filling) periods.
C) Low Pressure Nodes: Identifying low pressure nodes (below 40
psi) during high demand periods. Areas at high elevations will
have low pressures even when tanks are full.
d) High Headloss Lines: Finding lines with unusually high head
loss (greater than 5 ft per thousand feet) that need to be replaced,
paralleled, or redesigned.
Water Supply and Distribution Plan 41
e) Fire Flows: Making sure that all nodes of the distribution system
are able to get sufficient fire flows, while maintaining a minimum
20 psi residual pressure.
For the ultimate system in Figure 7, the very few pressures go below 40 psi and few
pressures never go above 90 psi. Head losses go above 5- ft/1000 ft only near the ground
storage tank in the 8 inch lines and some of the smaller lateral lines that dead end or are
considered services. Tanks have acceptable minimum levels, good ending levels, and
proper operating times.
Most areas are able to meet or exceed the following fire flow recommendations while
maintaining sufficient residual pressures: Residential = 1,000 gpm, Commercial/
Industrial = 3,500 gpm.
The following junctions do not meet the above criteria. All of these locations are in
existing areas where it would be difficult to improve the fire flows. If streets are replaced
in these areas in the future, consideration should be given to increasing main sizes in
these areas.
Table 15. Areas Below Design Fire Flows
JUNCTION
FIRE FLOW
Required (gpm)
Available (gpm)
380 (Washington County)
3,500
2800
1005 (Wash. County)
3,500
1,890
1006 (Wash. County)
3,500
1,690
1030 (Panama/65 )
1,000
920
(1) Washington County has a separate fire service connected to the main on Oxboro
Avenue.
Water System Phasing
Oak Park Heights' projected population for the year 2020 is 7,500. Based on the
projected population growth and water demands as shown in Table 8, additions to the
supply and storage facilities were estimated and are presented in Table 16. These
additions will keep pace with the increasing needs of the service area and at the same
Water Supply and Distribution Plan 42
time maintain a desirable balance between storage and supply for economy and
reliability. If growth rates deviate from the rates outlined in this report or if a major
water consumer is added to the system, the phasing schedule should be revised in
accordance with the latest available data. Note that due to the long construction period
for supply and storage facilities, wells and reservoir construction must begin one to two
years before they are actually required. Acquisition of sites should be done much sooner.
The data presented in Table 16 is based on the assumption that new wells will provide an
average capacity of 800 gpm and that one complete standby well will be provided.
Trunk water mains should be added as development occurs. The Capital Improvement
Plan presented in Table 18 is the best estimate of amount of trunk water main that will be
required each year.
Water Supply and Distribution Plan 43
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Economic Analysis
Cost Estimates
One of the basic objectives of this report was to determine the cost of completing Oak
Park Heights' water supply and distribution system for use in determining trunk water
charges and developing a Capital Improvement Plan. The cost estimates presented in this
report were based on August 1998 construction costs and can be related to the value of
the ENR Index for Construction costs of 5929 (August 1998). Future changes in this
index are expected to fairly accurately describe cost changes in the proposed facilities.
During interim periods, between full evaluation of projected costs, capital recovery
procedures can be related to this index. A summary of the estimated total costs of future
water supply, storage, and trunk distribution facilities is presented in Table 17. Cost
estimates for all items include 35% for contingencies and administrative, legal, and
engineering costs.
Only 8 inch to 16 inch trunk pipes were included in the distribution estimate. Laterals are
paid for out of development charges. Appendix C presents a more detailed cost estimate.
Table 17. Water System Cost Summary
Supply
$ 2,800,000
Storage
$ 1,080,000
Distribution
$ 5,164,000
Total Water System Cost
$ 9,044,000
Water Supply and Distribution Plan 45
Capital Improvement Program
A capital improvement program for the Oak Park Heights' water system is presented in
Table 18. The table shows the facility, the estimated cost, and the total expenditure for
the time period. The capital improvement program has been based on the supply /storage
phasing of Table 16.
Costs for the distribution system improvements have also been included in Table 18.
However, actual trunk and lateral distribution costs are highly dependent on the
development patterns of the City. These costs should be adjusted according to the
development plan of the City.
Water Supply and Distribution Plan 46
Table 18. Water System Capital Improvement Program
YEAR
IMPROVEMENT
ESTIMATED
COST
1998
Trunk Water Main
$ 341,200
1999
Trunk Water Main
$ 1,884,700
2.0 MG Ground Storage Tank
$ 1,080,000
Booster Station
$ 650,000
l Well
$ 700,000
5 PRVs (2 new, 3 replace)
$ 250,000
2000
Trunk Water Main
$ 243,300
2005
Trunk Water Main
$ 98,400
2010
Trunk Water Main
$ 219,000
2020
Trunk Water Main
$ 925,400
1 Well
$ 700,000
1 PRV
$ 50,000
Ultimate
Trunk Water Main
$ 502,000
2 Wells
$ 1,400,000
Total Ultimate Water System
$ 9,044,000
Water Charges
It is common practice to establish a policy of paying for the capital improvements with a
combination of lateral benefit, area charges, and connection charges. This method allows
the City to assess developable property for a portion of the trunk facilities costs at the
time the facilities are constructed. This "area charge" is based on gross benefited area.
Connection charges are then assessed at the time of hookup and are used to finance the
Water Supply and Distribution Plan 47
remaining capital cost. These charges should be reviewed and adjusted annually,
according to the ENR construction cost index.
Lateral Benefit
Lateral benefit is the portion of the cost of a trunk water main that would normally be
paid for by the developer. Any development in Oak Park Heights would be expected to
pay for an 6 inch water main to serve residential development and a 12 inch main to serve
commercial1industrial development. An estimate of the revenue the City would receive
through lateral benefit is shown in Table 19,
Table 19 — Lateral Benefit Estimate
Total Length of Ultimate System Trunk Mains
75,172 ft.
Minus Trunk Mains with no lateral benefit
18,566 ft.
6,264'— 16 inch
12,302' — 12 inch
Subtotal
56,606 ft.
Assume 50% of length is assessible
28,303 ft.
Assume both sides of street assessible
56,606 ft.
Assessible cost of 6 inch main
$18 /ft.
TOTAL LATERAL BENEFIT
$1,020,000
Area Charges
There are no set rules for the percentage of the capital costs to be paid for with area
charges and the percentage to be paid for with connection charges. The installation of
trunk water main is largely dependent on the area that is to be served. The cost of trunk
water main over- sizing is generally assigned on an area basis to the benefited properties.
The supply and storage facilities required are related to both the area served and the
number of connections. For the purposes of this report, it is assumed that 100% of all
trunk water main costs and 25% of all supply, and storage costs will be recovered through
area charges with the balance recovered through connection charges.
Water Supply and Distribution Plan 48
The estimated total gross developable area in Oak Park Heights is 3,070 acres. Based on
the criteria and assumptions described above, the area charges are as follows:
Table 20. Area Charge Requirements
AREA CHARGE REQUIREMENTS
Total Distribution System Cost
$ 5,164,000
Lateral Benefit
$ 1,020,000
Net Distribution System Cost
$ 4,144,000
25% of Supply and Storage Cost
$ 970,000
Total Area Charge Costs
$ 5,114,000
Total Developable Area (acres)
1,360
Area Charge (per acre)
$ 3J60
Water Supply and Distribution Plan 49
Connection Charges
Water supply, and storage facilities required in the provision of an overall water system
can be directly related to the amount and type of development experienced by a
community. It is a common practice to recover the majority of cost for these facilities on
a connected unit basis. As described above, this report assumes 75% of the supply and
storage facility costs will be collected through connection charges. The following table
presents estimated connections for Oak Park Heights based on future land use and
anticipated revenue.
Table 21. Estimated Number of Connections
Land Use Type
Area (acres)
Residential Equivalent
Units/Acre
Total Units
Low Density
Residential (LDR)
590
3.2
1,888
Multiple Family
Residential (MFR)
160
12
1,920
Commercial
170
4
680
Industrial
440
4
1,760
TOTAL
1 1,360
1 6,248
The calculation of the average connection charge is presented below.
Table 22. Connection Charge Requirements
75% of Supply Cost
75% of Storage Cost
Total Connection Charge Costs
Number of REU's
Connection Charge
Comparison to Existing Connection Charge
Existing charge: Based on 60 percent of total cost.
Commercial/Industrial
$ 2,100,000
$ 810,000
$ 2,910,000
6,248
$465 per REU
$4,010 /acre
Residential $2,110 /acre + $475 /unit
Water Supply and Distribution Plan 50
Proposed: Area charge was based on distribution cost minus lateral
benefit. Connection charge was based on 75 percent of
storage and supply costs.
Total Charge: $3,760 /acre + $465 /unit
Or $5,900 /acre
Water Supply and Distribution Plan 51
CITY OF OAK PARK HEIGHTS
Appendix A - Model Input
APPENDIX A - DEMANDS
Node
Label
Max Day
Demand
(gpm)
Peak Hour
Demand
(gpm)
5
30.7
61.3
10
0.0
0.0
15
6.1
12.1
16
10.6
21.2
20
14.6
29.2
25
7.6
15.1
30
0.0
0.0
32
0.0
0.0
34
44.5
89.0
35
0.0
0.0
40
5.0
10.1
45
0.0
0.0
50
17.5
34.9
55
0.0
0.0
60
0.0
0.0
65
0.0
0.0
70
0.0
0.0
75
4.0
8.1
80
3.5
7.1
85
0.0
0.0
90
17.6
35.3
92
7.6
15.1
100
0.0
0.0
101
0.0
0.0
105
0.0
0.0
110
0.0
0.0
115
0.0
0.0
120
0.0
0.0
125
8.6
17.1
130
5.0
10.1
135
5.6
11.1
140
8.1
16.1
145
8.1
16.1
150
11.6
23.2
155
3.0
6.1
160
4.0
8.1
165
1.5
3.0
170
5.0
10.1
175
5.6
11.1
180
4.5
9.1
185
4.5
9.1
190
5.6
11.1
195
6.1
12.1
200
9.1
18.1
205 7.1 14.1
Node
Label
Max Day
Demand
(gpm)
Peak Hour
Demand
(gpm)
210
9.1
18.1
215
7.1
14.1
220
6.1
12.1
225
10.1
20.2
230
8.6
17.1
235
11.6
23.2
240
3.5
7.1
245
12.1
24.2
250
9.6
19.2
255
5.0
10.1
260
16.0
31.9
265
19.5
38.9
270
0.0
0.0
275
4.0
8.1
280
10.1
20.2
285
19.2
38.3
290
67.1
134.1
295
58.0
116.0
300
15.1
30.2
305
31.3
62.5
310
8.6
17.1
315
3.5
7.1
320
5.0
10.1
325
4.5
9.1
330
5.6
11.1
335
9.6
19.2
340
12.1
24.2
345
0.0
0.0
350
0.0
0.0
355
0.0
0.0
360
0.0
0.0
365
0.0
0.0
370
8.6
17.1
375
4.0
8.1
380
71.3
142.6
382
0.0
0.0
384
0.0
0.0
385
0.0
0.0
386
0.0
0.0
390
0.0
0.0
1000
4.5
9.1
1005
0.0
0.0
1006
0.0
0.0
1007
0.0
0.0
1010 5.6 11.1
APPENDIX A - DEMANDS
Node
Label
Max Day
Demand
(gpm)
Peak Hour
Demand
(gpm)
1015
8.1
16.1
1020
7.6
15.1
1025
6.6
13.1
1030
2.5
5.0
1035
5.6
11.1
1040
3.5
7.1
1045
6.1
12.1
1050
8.1
16.1
1055
8.1
16.1
1060
4.0
8.1
1065
2.0
4.0
1066
0.0
0.0
1068
0.0
0.0
1070
11.6
23.2
1075
6.6
13.1
1080
9.1
18.1
1085
4.0
8.1
1090
4.0
8.1
1095
0.0
0.0
2000
5.0
10.1
2005
4.5
9.1
2010
1.5
3.0
2012
22.2
44.4
2015
16.1
32.3
2020
0.0
0.0
2025
14.0
27.9
2030
0.0
0.0
2035
13.5
26.9
2045
5.0
10.1
2050
5.0
10.1
2055
34.8
69.6
2060
5.0
10.1
2065
21.2
42.3
2070
10.6
21.2
2075
23.2
46.4
2080
25.2
50.4
2085
10.1
20.2
2090
11.1
22.2
2095
12.1
24.2
2100
11.1
22.2
2105
13.1
26.2
2110
0.0
0.0
2115
10.1
20.2
3000
176.1
352.2
3005
139.3
278.6
Node
Label
Max Day
Demand
(gpm)
Peak Hour
Demand
(gpm)
3010
258.7
517.4
3015
0.0
0.0
3020
0.0
0.0
3025
51.7
103.4
3030
0.0
0.0
3035
76.8
153.6
3040
139.1
278.2
3045
88.7
177.4
3050
-800.0
-800.0
3055
181.4
362.8
3060
89.4
178.6
3062
0.0
0.0
3064
0.0
0.0
3065
0.0
0.0
3070
- 3000.0
- 3000.0
3075
153.7
307.4
3080
0.0
0.0
3085
80.1
160.2
3090
132.1
264.2
3095
116.2
232.4
3100
0.0
0.0
3105
58.0
116.0
3106
- 2000.0
- 2000.0
3107
2000.0
2000.0
3108
0.0
0.0
3110
63.4
126.8
3115
0.0
0.0
3120
153.7
307.4
3125
198.2
396.4
3130
154.1
308.2
3135
63.4
126.8
3140
0.0
0.0
3145
93.5
187.0
3150
93.5
187.0
CITY OF OAK PARK HEIGHTS
Appendix B — Pressures and Elevations
APPENDIX B
Oak Park Heights - Water Supply and Distribution Plan
PRESSURES AND ELEVATIONS
STATIC RESIDUAL
Hydraulic Hydraulic
Node Elevation Grade Pressure Grade Pressure
10
935.0
1083.8
64.5
1077.48
61.7
15
937.0
1083.8
63.6
1079.16
61.6
16
944.9
1083.8
60.2
1079.21
58.2
20
944.0
1083.8
60.6
1080.04
59.0
25
933.0
1083.8
65.3
1079.68
63.6
30
934.0
1083.8
64.9
1079.85
63.2
32
951.0
1083.8
57.5
1080.5
56.1
34
951.0
1083.8
57.5
1080.5
56.1
35
925.0
1083.8
68.8
1079.83
67.1
40
930.0
1083.8
66.6
1078.72
64.4
45
935.0
1083.8
64.5
1080.66
63.1
50
942.0
1083.8
61.4
1080.93
60.2
55
938.0
1083.8
63.2
1081.58
62.2
60
939.0
1083.8
62.7
1081.46
61.7
65
938.0
1083.8
63.2
1082.16
62.5
70
938.0
1083.8
63.2
1081.79
62.3
75
930.0
1083.8
66.6
1080.77
65.3
80
932.0
1083.8
65.8
1080.49
64.3
85
910.0
1083.8
75.3
1079.92
73.6
90
918.0
1083.8
71.8
1079.91
70.2
92
940.0
1083.8
62.3
1081.88
61.5
100
940.0
1083.8
62.3
1081.88
61.5
101
940.0
1083.8
62.3
1081.88
61.5
105
957.0
1083.8
54.9
1081.88
54.1
110
957.0
1083.8
54.9
1084.27
55.2
115
943.0
1083.8
61.0
1082.7
60.5
120
957.0
1083.8
54.9
1084.19
55.1
125
953.0
1083.8
56.7
1084.69
57.1
130
941.0
1083.8
61.9
1084.9
62.4
135
948.0
1083.8
58.8
1085.18
59.4
140
939.0
1083.8
62.7
1084.04
62.9
145
960.0
1083.8
53.6
1084.98
54.2
150
951.0
1083.8
57.5
1085.4
58.2
155
924.0
1083.8
69.2
1087.79
71.0
160
920.0
1083.8
71.0
1088.34
72.9
165
907.0
1083.8
76.6
1087.15
78.1
170
915.0
1083.8
73.1
1086.93
74.5
175
927.0
1083.8
67.9
1086.39
69.1
180
947.0
1083.8
59.3
1084.73
59.7
185
918.0
1083.8
71.8
1086.53
73.0
MR
il�Z:l•�i�:1•�:1
200 929.0 1083.8 67.1 1083.11 66.8
210 920.0 1083.8 71.0 1082.38 70.4
215 908.0 1083.8 76.2 1082.21 75.5
220 903.0 1083.8 78.3 1082.13 77.6
230
932.0
1083.8
65.8
1082.89
76.8
65.4
275
235
940.0
1083.8
62.3
1082.74
61.9
902.0
240
943.0
1083.8
61.0
1082.66
900.0
60.5
79.6
245
933.0
1083.8
65.3
1082.36
1083.8
64.7
1084.83
250
930.0
1083.8
66.6
1082.36
62.3
66.0
68.4
255
932.0
1083.8
65.8
1082.47
1081.19
65.2
260
905.0
1083.8
77.5
1079.68
93.3
75.7
310
270
904.0
1083.8
77.9
1081.15
76.8
275
893.0
1083.8
82.7
1081.89
81.9
280
902.0
1083.8
78.8
1082.15
78.1
285
900.0
1083.8
79.6
1082.69
79.2
290
883.0
1083.8
87.0
1084.83
87.5
295
940.0
1083.8
62.3
1097.92
68.4
300
873.0
1083.8
91.3
1081.19
90.2
305
866.0
1083.8
94.4
1081.22
93.3
310
859.0
1083.8
97.4
1081.32
96.3
315
872.0
1083.8
91.8
1081.47
90.8
320
877.0
1083.8
89.6
1081.59
88.7
325
894.4
1083.8
82.1
1081.72
81.2
330
878.0
1083.8
89.2
1081.5
88.2
335
884.0
1083.8
86.6
1081.35
85.5
340
890.0
1083.8
84.0
1081.17
82.8
345
910.0
1083.8
75.3
1080.4
73.8
350
905.0
1083.8
77.5
1079.86
75.8
355
908.0
1083.8
76.2
1079.31
74.2
360
929.6
1083.8
66.8
1079.2
64.8
365
920.0
1083.8
71.0
1079.11
68.9
370
918.0
1083.8
71.8
1078.47
69.5
375
918.0
1083.8
71.8
1078.23
69.4
380
925.0
1083.8
68.8
1077.35
66.0
382
910.0
1083.8
75.3
1077.35
72.5
384
880.0
1083.8
88.3
1076.05
85.0
385
886.0
1083.8
85.7
1076.95
82.7
386
772.0
1001
99.2
1001.51
99.5
390
897.0
1083.8
80.9
1079.16
78.9
1000
866.0
1001
58.5
1000.66
58.4
1005
893.0
1001
46.8
999.43
46.1
1006
895.0
1001
45.9
998.74
45.0
1007
897.0
1001
45.1
997.34
43.5
1010
895.0
1001
45.9
995.94
43.7
1015
895.0
1001
45.9
994.7
43.2
1020
895.0
1001
45.9
994.23
43.0
1025
887.0
1001
49.4
994.09
46.4
1030 884.0 1001 50.7 994.06 47.7
1035 865.0 1001 58.9 994.02 55.9
1045 836.0 1001 71.5 994.01 68.5
1050 834.0 1001 72.4 994.01 69.3
1055 845.0 1001 67.6 994.09 64.6
1060 878.0 1001 53.3 995.94 51.1
1070 870.0 1001 56.8 996 54.6
1080
820.0
1001
78.4
993.2
75.1
1085
785.0
1001
93.6
993.67
90.4
1090
800.0
1001
87.1
992.14
83.3
1095
811.0
1001
82.3
989.54
77.4
2000
780.0
898
51.1
898.26
51.2
2005
765.0
898
57.6
897.4
57.4
20 700.0 898 85.8 _ 895.78 84.8
2015 750.0 898 64.1 896.01 63.3
2020 700.0 898 85.8 895.74 84.8
2025 698.0 898 86.7 895.72 85.7
2035 685.0 898 92.3 895.7 91.3
2045 771.0 898 55.0 897.39 54.8
2050 771.0 898 55.0 897.09 54.6
:kI: :k1/PIMII
. I 11
2075
760.0
898
59.8
896.7
59.2
2080
782.0
898
50.3
896.68
49.7
2085
785.0
898
49.0
897.06
48.6
2090
786.0
898
48.5
896.68
48.0
2095
788.0
898
47,7
896.7
47.1
2105
780.0
898
51.1
897.83
51.1
2110
825.0
898
31.6
898.47
31.8
2115
795.0
898
44.6
898.15
44.7
3000
940.0
1083.8
62.3
1075.87
58.9
3005
940.0
1083.8
62.3
1075.25
58.6
3015 938.0 1083.8 63.2 1075.76 59.7
3020 948.0 1083.8 58.8 1077.84 56.3
3025 952.0 1083.8 57.1 1078.55 54.8
3035 952.0 10 83.8 57.1 1080.16 55.5
3040
935.0
1083.8
64.5
1084.04
64.6
3045
952.0
1083.8
57.1
1083.78
57.1
3050
954.0
1083.8
56.2
1084.32
56.5
3055
954.0
1083.8
56.2
1080.12
54.7
3Ut52
820.0
1083.8
114.3
1078.7
112.1
3064
820.0
1001
78.4
1000.54
78.2
3065
900.0
1083.8
79.6
1094.7
84.4
3070
950.0
1083.8
58.0
1108.17
68.5
3075
920.0
1083.8
71.0
1100.65
78.3
3080
900.0
1083.8
79.6
1097.93
B5.8
3085
838.0
1001
70.6
963.51
54.4
3090
860.0
1001
61.1
963.22
44.7
3095
850.0
1001
65.4
964.55
49.6
3100
850.0
1001
65.4
966.82
50.6
3105
900.0
1083.8
79.6
1097.04
85.4
3106
930.0
1083.8
66.6
1099.07
73.3
3107
930.0
1083.8
66.6
967.89
16.4
3108
930.0
1083.8
66.6
1055.11
54.2
3110
880.0
1083.8
88.3
1097.39
94.2
3115
930.0
1083.8
66.6
1097.18
724
3120 930.0 1083.8 66.6 1097.24 72.5
ry'Ki]
3135
900.0
1083.8
79.6
1097.49
85.6
3140
750.0
1001
108.8
963.43
92.5
3145
700.0
898
85.8
B96.23
85.0
898 85.8
CITY OF OAK PARK HEIGHTS
Appendix C — Cost Estimates
Appendix C - Ultimate System Cost Estimates
SUPPLY
Item Unit Cost Quantity Total
800 gpm Jordan Aquifer $700,000 4 $2,800,000
Wells and Pumphouses
$2,800,000
STORAGE FACILITIES
Item Unit Cost Quantity Total
2.0 MG Ground Storage Tank $1,080,000 1 $1,080,000
$1,080,000
DISTRIBUTION
Item
Unit Cost
Quantity
Total
8" Water Main
$45
8,083
$364,000
12" Water Main
$55
60,115
$3,306,000
16" Water Main
$70
7,774
$544,000
Booster Station
$650,000
1
$650,000
Pressure Reducing Valves
$50,000
6
$300,000
$5,164,000
TOTAL ULTIMATE SYSTEM COST SUMMARY
Supply $2,800,000
Storage 1,080,000
Distribution 5,164,000
$9,044,000
Appendix C
Oak Park Heights
Water Main Cost Estimates
Year to
Install
Start
Node
End
Node
Length
(ft)
Diameter
(in)
Cost
($)
1998
5
3000
862
12
$47,410
32
3045
1,743
12
$95,865
3000
3005
2,145
12
$117,975
3045
3050
1,454
12
$79,970
Total
6,204
$341,200
1999
1068
3064
141
8
$6,345
20
3055
1,071
12
$58,905
32
3055
718
12
$39,490
65
3050
1,029
12
$56,595
80
265
2,506
12
$137,830
80
345
723
12
$39,765
110
3050
630
12
$34,650
145
3050
639
12
$35,145
155
3040
1,190
12
$65,450
365
3090
285
12
$15,675
265
3060
2,166
12
$119,130
295
Prison
800
12
$44,000
1000
3064
655
12
$36,025
2055
2070
1,525
12
$83,875
3005
3110
900
12
$49,500
3010
3015
767
12
$42,185
3030
3035
1,392
12
$76,560
3035
3055
1,337
12
$73,535
3035
3040
2,144
12
$117,920
3060
3062
92
12
$5,060
3062
PRV 9
104
12
$5,720
3100
3140
1,490
12
$81,950
3140
PRV 8
379
12
$20,845
PRV 8
2055
1,614
12
$88,770
PRV 9
3064
102
12
$5,610
155
160
368
16
$25,760
160
3065
1,655
16
$115,850
295
3105
1,336
16
$93,520
295
3107
512
16
$35,840
3065
3105
2,642
16
$184,940
3100
3107
1,261
16
$88,270
Total
32,173
$1,884,700
2000
3015
3020
3,085
12
$169,675
3020
3025
1,059
12
$58,245
3025
3030
279
12
$15,345
Total
1
4,423
$243,300
2005
140
3040
840
12
$46,200
140
3045
949
12
$52,195
Total
1,789
$98,400
2010
3085
3090
1,333
12
$73,315
3085
3095
1,988
12
$109,340
3095
3100
664
12
$36,520
Total
3,985
$219,000
2020
295
3135
1,350
12
$74,250
2015
3150
1,576
12
$86,680
2070
3145
1,740
12
$95,700
3065
3070
2,634
12
$144,870
3070
3075
1,319
12
$72,545
3075
3080
1,319
12
$72,545
3080
3130
1.323
12
$72,765
3130
3135
1,304
12
$71,720
3130
PRV6
1,322
12
$72,710
3145
3150
2,282
12
$125,510
PRV6
3085
657
12
$36,135
Total
16,826
$925,401)
2045
Ultimate
3075
3120
1,330
8
$59,850
$59,850
3080
3115
1,330
8
3110
3135
1,319
8
$59,355
3115
3120
1,319
8
$59,355
3115
3125
1.319
8
$59,355
$59,625
3125
3130
1,325
8
3080
3110
1,3 24
12
$72,820
3105
3110
1,306
12
$71,830
Total
10,572
$502,000
Total Water
b1ain
75,972
4,214,000
CITY OF OAK PARK HEIGHTS
Appendix D — Water Quality Requirements
Appendix D - Water Quality Requirements
Background
In 1977, the U.S. Environmental Protection Agency (EPA) established the National Interim Primary
Drinking Water Regulations (NIPDWR). Development under the Safe Drinking Water Act (PL 93-
523), these regulations contain federally enforceable maximum contaminant level (MCL) standards
for substances known to be hazardous to public health. Based largely upon the Public Health Service
Standards of 1962, these regulations include requirements on the frequency of testing and the
subsequent reporting of test results.
Between 1977 and 1983, four amendments were made to the NIPDWR that increased the number
of water quality parameters for which MCL's were assigned. During the mid- 1980's, an increase in
public awareness of water quality and contamination resulted in promulgation of the 1986 Safe
Drinking Water Act amendments. These amendments mandated the current review of existing
MCL's and the development of still more water quality standards and treatment requirements for all
public drinking water supplies.
Over the past few years there have been several more amendments added to those of the Safe
Drinking Water Act, and still more are planned for the future. This is because the EPA has identified
over 65 new substances that need to be regulated. Permissible levels for these substances will be
proposed and implemented over the next few years.
Under the Safe Drinking Water Act, water quality parameters are defined and regulated by two
separate sets of criteria or standards — Primary and Secondary. In 1991, the EPA included a lead and
copper rule to the Primary Standards. A discussion of these Standards follows.
This appendix also contains a discussion about water hardness and how it relates to water quality.
Appendix D —1998 Water Supply & Distribution Plan D -1
National Primary Standards
Primary Drinking Water Standards identify maximum containment levels (MCL's) for those
substances known to be harmful to public health. Enforcement of these standards is under the
jurisdiction of the Minnesota Department of Health. The Primary Drinking Water Standards are
divided into five categories with MCL's being determined for each contaminant. The five categories
are:
(1) Inorganic.
(2) Synthetic Organic Chemicals (SOC's).
(3) Volatile Organic Chemicals (VOC's).
(4) Microbiological.
(5) Radiological.
A listing of the five categories, the type of water to which they are applicable, the contaminants
included in each, and the MCL are presented at the back of this appendix. Both existing and
proposed regulations are presented.
Testing for coliform bacteria and inorganic chemicals is required in all public water systems. The
number of coliform density samples required under the law is proportionate to the population served
by the system. Testing for turbidity and organic chemicals is required by law for public water
systems utilizing a surface water source. The State can require testing for organic chemicals and
radiological chemicals in certain groundwater supplies.
Lead and Copper Rule
In July of 1991, the lead and copper rule was promulgated by the EPA. Included in the Primary
Drinking Water Standards, the lead and copper rule requires treatment when lead and/or copper in
a public water supply exceeds the action levels of 0.015 mg/L for lead (Pb) and 1.3 mg/L for copper
(Cu). Lead and copper enter drinking water mainly from the corrosion of lead and/or copper
distribution and service piping. For this reason, contamination by these elements primarily takes
place after the water enters the distribution system and testing must be done at the point -of -use.
Appendix D —1998 Water Supply & Distribution Plan D -2
To comply with the new laws, all water utilities must complete a materials evaluation of their
distribution system and/or review other information to target high risk homes. The water utilities
must then complete an initial sampling survey of site within the service area. The number of
sampling sites is based on the population served and listed below. One sample is to be taken from
each site. Each sample is to be "first- draw" following a period of stagnant flow.
Initial Monitoring for Lead and Conner
System Size
Minimum Number
Date Sampling
(Population)
Of Samples
Begins
>100,000
100
January 1992
50,000 to 100,000
60
January 1992
10,000 to 50,000
60
July 1992
3,300 to 10,000
40
July 1992
500 to 3,300
20
July 1993
100 to 500
10
July 1993
<I00
5
July 1993
Initially, municipal utility departments are required to collect home tap samples for lead and copper
analysis every six months. In systems that are required to install corrosion control treatment,
follow -up samples for other water quality parameters (WQPs) must be taken from within the
distribution system every six months and from entry points to the distribution system every two
weeks. Both the number of sampling sites and the frequency may be reduced if the action level is
met or the system maintains optimal treatment. Sampling frequency is summarized below.
Appendix D —1998 Water Supply & Distribution Plan D -3
Lead and Conner Sampling Frequency
Pb /Cu
WOPs
Within The At entry to
Distribution Distribution
Monitoring Period eriod Home Tans System System
initial tests 6 mo. 6 mo. 6 mo.
After corrosion
treatment 6 mo. 6 mo. 2 wk.
Reduced
Conditional
l yr.
6 mo.
2 wk.
Final
3 yr.
3 yr.
2 wk.
Four types of action are required to remedy high lead/copper levels. Once a system has more than
10 percent of all tap monitoring results exceed the action levels, the system must perform corrosion
control treatment, source water treatment and public education. If the system continues to exceed
the action levels, service line replacement is required.
To optimize treatment and determine compliance with State lead/copper standards, additional
monitoring must be performed on systems meeting the following conditions:
- Large systems serving more than 50,000 persons, regardless of the lead/copper levels
in tap samples.
- Smaller systems serving less than 50,000 persons, if either action level is exceeded in
tap samples.
Testing for other WQPs such as pH, alkalinity, calcium, conductivity, orthophosphate, silica and
temperature, occurs at two types of sampling sites:
- Within the distribution system, with the number of sites based on the population served.
Two samples are required from each site.
- One sample at each entry point to the distribution system.
Appendix D —1998 Water Supply & Distribution Plan D -4
Secondary Standards
In addition to the hazardous contaminants covered by the Safe Drinking Water Act, concentrations
of other substances, not having an impact on public health, frequently cause drinking water supplies
to have objectionable aesthetic qualities, such as taste and odor. Because of this, Secondary
Drinking Water Standards were developed to act as a guide in suggesting the maximum contaminant
level for select chemical and physical characteristics of a water supply. The Secondary Standards
generally imply that public water supplies exceeding the maximum suggested levels will have more
customer complaints than those not exceeding the suggested levels. A summary of the Secondary
Drinking Water Standards is presented below.
Secondary Drinking Water Standards
Maximum Contaminant Level
1. Regulated Parameter Current
2. Proposed Parameter to be Regulated Proposed
MCL (me/L)
Hexachlorocyclopentadiene 0.008
* TON - Threshold Odor Number
Appendix D -1998 Water Supply & Distribution Plan D -5
MCL
Oak Park Heights'
(me/L)
Raw Water
Aluminum
0.05-0.2
Chloride
250
Color
15 color (units)
Copper
1
Corrosivity
noncorrosive
Fluoride
2
1.2
Foaming Agents
0.5
Iron
0.3
Manganese
0.05
Odor
3 TON*
pH
6.5-8.5
Silver
0.10
Sulfate
250
8.6 -11.0
Total Dissolved Solids (TDS)
500
Zinc
5
2. Proposed Parameter to be Regulated Proposed
MCL (me/L)
Hexachlorocyclopentadiene 0.008
* TON - Threshold Odor Number
Appendix D -1998 Water Supply & Distribution Plan D -5
Hardness
Hardness is another water quality concern. The United States Geological Survey and the American
Water Works Association have established the following standards for hardness.
Hardness Classification
Hardness (mgtl)
Classification
Oak Park
Heights'
Water
0-75
Soft
75 -150
Moderate] Hard
150 -300
Hard
210
> 300
Very Hard
The most common objections to hard water are:
1. Consumption of large quantities of soaps and detergents,
2. Adverse effect on clothing and other articles being cleansed,
3. Shortening of the life of pipes and fittings, heating systems, and boiler shells and tubes,
and
4. Unsuitability for many industrial uses.
An upper limit for hardness has never been established due to the broad range of customer
tolerances, but water with a hardness of 70 - 85 mgll is usually considered desirable for residential
and commercial uses.
Appendix D —1998 Water Supply & Distribution Plan D -6
NATIONAL PRIMARY STANDARDS FOR DRINKING WATER
MAXIMUM CONTAMINANT LEVELS
A) INORGANIC CHEMICALS
(Surface & Ground Water)
1. Existing Regulated
Inorganic Chemicals
Current
Contaminant MCL (nab)
Arsenic
50
Asbestos
7 MFL
Barium
2,000
Cadmium
5
Chromium (total)
100
Fluoride
4,000
Lead
TT*
Mercury
2
Nitrate (as N)
10,000
Nitrite (as N)
1,000
Selenium
50
2. Proposed Inorganic
Chemicals to be Regulated
Proposed
Contaminant MCL (nnb)
Antimony
5-10
Beryllium
1
Copper
1,300
Cyanide
200
Nickel
100
Sulfate
400 - 500 mg/l,
Thallium
1-2
* TT - Treatment Technique for lead is triggered by a 15 ppb action level.
Appendix D —1998 Water Supply & Distribution Plan D -7
B) SYNTHETIC ORGANIC CHEMICALS (SOCs)
(Surface & Ground Water)
Current
1. Existing Regulated SOCs MCL (ppb)
Acrylamide
TT*
Alachlor
2
Aldicarb
3
Aldicarb Sulfone
2
Aldicarb Sulfoxide
4
Atrazine
3
Carbofuran
40
Carbon Tetrachloride
5
Chlordane
2
Dibromochloropropane (DBCP)
0.2
o- Dichlorobenzene
600
p- Dichlorobenzene
75
1,2- Dichloroethane
5
1,1- Dichloroethylene
7
cis -1,2- Dichloroethylene
70
trans -1,2- Dichloroethylene
100
2,4- Dichlorophenoxyacetic Acid (2,4 -D)
70
1,2- Dichloropropane
5
Epichlorohydrin
TT*
Ethylbenzene
700
Ethylene Dibromide (EDB)
0.05
Appendix D —1998 Water Supply & Distribution Plan D -8
National Primary Standards (Continued)
500
Heptachlor
0.4
Heptachlor Epoxide
0.2
Hexachlorocyclopentadiene
50
Lindane
0.2
Methoxychlor
40
Monochlorobenzene
100
PCBs
0.5
Styrene
100
Tetrachloroethylene
5
Total Trihalomethanes
100
Toluene
1,000
Toxaphene
5
2,4,5 -TP (silvex)
50
1, 1, 1 -Trichloroethane
200
Trichloroethylene
5
Vinyl Chloride
2
Xylenes (total)
10,000
2. Proposed SOCs to be Regulated MCL (nnb)
Adipates
500
Dalapon
200
Dichloromethane (methylene chloride)
5
Dinoseb
7
Diquat
20
Endothall
100
Endrin
2
Glyphosate
700
Appendix D —1998 Water Supply & Distribution Plan D -9
National Primary Standards (Continued)
Proposed
Hexachlorobenzene
1
Hexachlorocyclopentadiene
50
Oxamyl (Vydate)
200
PAHs (Polynuclear Aromatic Hydrocarbons)
0.2
Pentachlorophenol
1
Phthalates
4
Picloram
500
Simazine
4
1,1,2 - Trichloroethane
5
2,3,7,8 -TCDD (Dioxin)
0.00005
1,2,4 - Trichlorobenzene
9
1,1,2 - Trichloroethane
5
C) VOLATILE ORGANIC CHEMICALS (VOCs)
(Ground Water)
Current
Contaminant
MCL (uob)
Benzene
5
Carbon Tetrachloride
5
p- Dichlorobenzene
75
1,2- Dichloroethane
5
1,1- Dichloroethylene
7
cis -1,2- Dichloroethylene
70
trans -1,2- Dichloroethylene
100
Tetrachloroethylene
5
Trichloroethylene
5
Vinyl Chloride
2
Appendix D —1998 Water Supply & Distribution Plan D -10
National Primary Standards (Continued)
D) MICROBIOLOGICAL
(Surface and Ground Water)
Giardia Lamblia
TT*
Legionella
TT*
Standard Plate Count
TT*
Total Coliforms
+ +*
Turbidity
PS*
Viruses
TT*
E) RADIOLOGICAL
(Surface & Ground Water)
Current Proposed
MCL MCL
Beta - particle and 4 mrem
photon emitters 4 mrem
Alpha Emitters 15 pCi/L
Radium 226 + 228 5 pCi/L
Radium 226 20 pCUL
Radium 228 20 pCi/L
Radon 300 pCi/L
Uranium 20 g/L
* Abbreviations used in this table:
++ - No more than 5% of the samples per month may be positive. (For systems
collecting fewer than 40 samples per month, no more than I sample per month
may be positive.)
TT - Treatment Technique
PS - Performance Standard 0.5 - 1.0 ntu (naphthalene turbidity unit)
Appendix D —1998 Water Supply & Distribution Plan D -11
CITY OF OAK PARK HEIGHTS
Appendix E - Water Emergency Plan
Water System Emergency Preparedness
Plan
Purpose
The purpose of this plan is to prepare a detailed description of procedures to follow in the
event of a disruption to normal water service. The disruption could be natural or man-
made, and could affect the entire water system or only parts of the system. This plan
cannot address all potential disasters. It is intended to give the water utility staff a
guideline to allow them to quickly restore normal water service with a minimum of
disruption, and to minimize any potential health risks. This plan should be coordinated
with the emergency plans of other City and regional entities; Police, Fire, Public Works,
etc.
Emergency Telephone List
The Emergency Telephone list is attached. Work and home phone numbers of key
emergency contacts and the 24 hour cellular contact are included on Oak Park Heights'
phone list, which is not included as a part of this document for data privacy reasons.
Also attached is an Emergency Information Reporting form. This form will not cover all
emergencies that the City may experience; however, the form will help standardize the
reporting/recording process. A standard question format will help staff persons collect
accurate and specific information about the emergency so that the proper response can be
initiated without delay.
Current Water Sources and Service Area
Oak Park Heights' DNR appropriation permit number is 75 -6123. There are a total of
1049 service connections as of January 1, 1998. Oak Park Heights does not have any
surface water sources. Oak Park Heights has two wells connected to the municipal
system, both of which are permanent sources. Both wells #1 and #2 are located in the
Jordan aquifer. A summary of the well data is included in Table E -1. A map illustrating
Appendix E — Water Supply & Distribution Plan E -1
the locations of existing and future wells is shown in the back of the report. A detailed
discussion of Oak Park Heights' water sources is found in the "Existing Facilities" section
of the Water Supply Description and Evaluation.
Procedure For Augmenting Water Supplies
The following alternatives exist for additional supplies of water.
Interconnect with Adjacent Communities
Currently, the City does not share any permanent interconnections with adjacent
communities. The following is a list of potential interconnections.
• Stillwater at Oakgreen Ave: A 12 inch connection should be made to Stillwater
when Highway 36 is reconstructed. Stillwater's water system operates at the same
high water level as Oak Park Heights in this area. Therefore, the connection can be
very simple — consisting of a valve (normally closed) and a meter to measure flow in
both directions.
• Stillwater at 65' and 62 " There are several hydrants in Stillwater east of Osgood
near 65 St. and 62 St. that are in close proximity to hydrants in Oak Park Heights.
These hydrant to hydrant connections are being used in the fall of 1998 to provide
water to Oak Park Heights north of Highway 36 while the City repairs a leaky water
main near Osgood.
• Procedure: Connections between Oak Park Heights and Stillwater will be
coordinated between Jay Johnson (Oak Park Heights Public Works Director) and Jim
McNight (Stillwater Water Board Chair). Jim McNight's phone number is 439 -6231.
Conjunctive Use of Surface and Ground Waters
Although Lake St Croix borders the City, the conjunctive use of surface and ground
waters is not a viable option for the City of Oak Park Heights at this time. It is not
considered a suitable source of water for water suppliers. It would be extremely costly
for Oak Park Heights to build water treatment plants with the necessary equipment to
treat surface water to potable standards.
Appendix E — Water Supply & Distribution Plan E -2
Alternative Sources of Water
The City of Oak Park Heights utilizes the Jordan aquifer. Other possibilities for water
supply provisions during extended emergency periods would be to either bring potable
water in via trucks, or investigate the possibility of purchasing water from neighboring
communities.
Demand Reduction Procedures
Demand reduction procedures should be initiated during unusually high demand periods
or shortage of water due to an emergency. The restrictions should relate to the severity of
the emergency or shortage.
Demand Reduction Potential
Oak Park Heights' usage during the summer months is higher than during the winter
months. In the future it is important that the city keep track of daily pumpage to improve
evaluation of demand reduction potential. For demand/supply emergencies during the
summer months, sprinkling bans can easily be instituted for all of the customer
categories. These sprinkling bans would have the potential for significant short-term
demand reduction. The City should initiate discussions with the Minnesota Correctional
Facility to determine short-term demand reduction potential at that facility.
Short -Term Demand Reduction Procedures
The following short-term demand reduction measures are a current part of Oak Park
Heights' conservation plan. The measures are progressively more stringent for use as the
length or severeness of the emergency warrants. Triggers for each of these measures are
outlined in the following sections.
Voluntary Reduction Measures: Public service announcements, door -to -door
notices, direct mailing, community bulletin boards, Cable T.V. and notices in the
local paper.
2. Sprinkling Bans: The City currently has a water policy that authorizes the City
Administrator to issue restrictions on lawn sprinkling at anytime (copy attached).
Appendix E — Water Supply & Distribution Plan E -3
3. Water Allocation Restrictions: Based on severity of emergency and water use
priorities established in next section.
Procedures for Water Allocation
Initial emergency response will include actions to augment supplies and/or reduce
demands. However, severe water shortages may require the City of Oak Park Heights to
allocate water based on the following priorities. These priorities are established by
Minnesota Statutes 103G.261.
Non - essential uses of water are the lowest use priority and will be the first water use
subject to allocation restrictions. Quick responses to restrict non - essential uses of water
during periods of limited supplies will help protect domestic and economic uses of water.
Therefore, the City of Oak Park Heights will be quick to step in and limit the non-
essential use of water.
First Priority. Domestic water supply, excluding industrial and commercial use of
municipal water supply, and use for power production (which currently does not apply
to Oak Park Heights) that meets contingency requirements.
Notify all customers
Second Priority. Water uses involving consumption of less than 10,000 gallons per
day.
Notify all commercial/industrial customers
Third Priority. Agricultural irrigation and processing of agricultural products.
Does not apply to Oak Park Heights
Fourth Priority. Power production in excess of the use provided for in the contingency
plan under first priority.
Does not apply to Oak Park Heights
Fifth Priority. Uses, other than agricultural irrigation, processing of agricultural
products, and power production.
Does not apply to Oak Park Heights
Appendix E — Water Supply & Distribution Plan E-4
Sixth Priority. Non - essential uses. These uses are defined by Minnesota Statutes
103G.291 as lawn sprinkling, vehicle washing, golf course and park irrigation, and
other non - essential uses.
Notify all customers
While initial emergency responses may include actions to augment supplies and/or
reduce demands, severe water shortages would require water allocation in accordance
with these priorities.
Triggers for Implementing Plan Components
The critical factor in the Oak Park Heights water system is the well pump supply. The
following triggers are initiated based on the percentage of well capacity. The triggers
will be updated when future wells are added.
Trigger
Measure % of Well Capacity MGD(1)
Firm Capacity: 1.15
Voluntary Reduction Measures Always Always
Odd/Even Sprinkling Ban 85 0.98
Total Sprinkling Ban 90 1.04
Eliminate 6th Priority Allocation 95 1.09
Eliminate 2nd Priority Allocation 100 1.15
(1) Firm capacity is the capacity of the wells with the largest well out of service.
Appendix E — Water Supply & Distribution Plan E -5
Enforcement
The City has a water policy that gives the City Administrator, in consultation with the
Publics Works Director, authorization to issue restrictions on lawn sprinkling. Such
restrictions may include an odd/even sprinkling ban or limitations on the hours of the day
or the days of the week during which lawn sprinkling is prohibited. In addition, the
Administrator may declare a total sprinkling ban if needed.
The focus of Oak Park Heights' short-term demand reduction plan is on voluntary
reduction of non - essential uses of water. The City mails notification of the possibility of
sprinkling bans with the spring bills. In this mailing the City informs customers that
notification of the sprinkling bans will be made in the City's two local papers, the
Gazette, and the Courier.
Enforcement will become more stringent as the emergency progresses. Odd/even
sprinkling bans will be monitored and enforced by the public works department and the
Oak Park Heights Police. Failure to comply with water use restrictions may be subject to
a misdemeanor.
Water Supply Protection
Analysis of Previous Supply Problems
No major repairs have been necessary and only a few minor water main breaks have
occurred. The City will be monitoring the original section of distribution piping more
closely as the system ages. All tools necessary for repairs of water lines and pump house
equipment are on hand at all times. The City also has access to pipes, valves and tools
from a local supplier at all hours. As the system ages and repairs become more necessary
the City will need to increase the supply of piping as well as valves, couplings, etc. to
reduce repair time.
Wellhead Protection
Water supply protection is an essential part of the Oak Park Heights water plan. The City
has started the wellhead protection planning process. The first phase of planning was
Appendix E — Water Supply & Distribution Plan E -6
completed in February, 1998 with a report by Northern Environmental entitled, Wellhead
Protection Area And Drinking Water Supply Management Area Delineations, And
Aquifer And Well Vulnerability Assessments.
Resource Monitoring
The City periodically measures the static water levels and pumping levels in their well
and will continue to do so in the future. This information will be used to detect significant
changes in aquifer conditions. In addition, MDH performs annual water quality testing at
each of the wells in accordance with the provisions of the Clean Water Act. Examples of
previous water quality lab results are included in Table E -1 of this plan.
Emergency Resources
A good maintenance program can identify potential problems before they become an
emergency. The City's water system is in excellent condition, due to a proactive
maintenance program. The following are the major components of Oak Park Heights
maintenance program, and recommendations for future improvements.
Valves: Valves are checked occasionally as personnel are available. The City needs
sufficient personnel on call during valve turning operations in case a valve breaks or a
leak develops.
Recommendations: Establish a schedule for valve turning, maintain better records on
valve maintenance, and have sufficient personnel available to repair any problems that
arise during valve exercising. Begin to organize valve data for the City's Geographic
Information System (GIS). Test all pressure reducing valves at least twice a year.
Hydrants: Every hydrant is checked once a year. Hydrants are also checked in the
winter to make sure they are dry. Their Fire Department is working with the Utility to
accurately map all hydrants.
Recommendations: Include hydrant data in the City GIS.
Appendix E — Water Supply & Distribution Plan E -7
Breaks/Repairs: The City maintains records of all breaks and repairs. Prior to any
street reconstruction project, the break record is reviewed to determine if pipe should
be replaced.
The City has an inventory of repair parts, valves, and sleeves at the Public Works
Department.
Recommendations: Include break locations on the City GIS.
LO=I
The City currently has purchased emergency backup power. The trailer mounted
generator is kept at City Hall. In the event of a power failure the generator will
automatically run for Well 1.
Recommendation: Establish a plan for utilizing emergency generators.
Labor
Oak Park Heights has an emergency contractors list, which specifies a variety of
contractors who have agreed to perform emergency services. The list has been included
in this plan.
Control System
The computerized control systems for water treatment and distribution are indispensable
to water supply operations. In case of an emergency, a municipality must have a well -
planned control system. Following are a number of alternatives to be considered for
preventing failure of a computerized control system:
1. Routine maintenance programs.
2. Backup power sources.
Communications Systems
Communication systems are vital to water supply operations. Unfortunately,
communication lines, such as telephone lines, are susceptible to many types of disasters
Appendix E— Water Supply & Distribution Plan E -8
(storms, construction accidents, etc.). Accordingly, it is important that backup
communication systems be maintained and tested regularly.
The City of Oak Park Heights alarms are sent to the same location as the City's Police
Department. Police department has personnel at this building 24 hours a day. In the
event of an emergency, the police department will contact the appropriate City Personnel.
Sensors
Water system sensors and detectors are important for recognizing and correcting
emergency situations. Pressure transducers and limit switches should be checked and
calibrated regularly.
Security
The safety of a water supply and distribution system is critical to any community, and
acts of vandalism or terrorism should never be allowed to compromise this valuable
resource. A security system including the use of electronic keys or some similar device
could be implemented to control access to water system facilities.
Currently all entrances to facilities are kept locked. Keys to entrances are provided only
to operators /maintenance personnel.
Operation and Maintenance Manuals
Operation and maintenance manuals are conveniently located throughout system facilities
so as to provide the public works staff with accessible instructions in case of an
emergency.
Replacement Parts
An adequate supply of replacement parts are stored at the water utility facilities as
recommended by the manufacturers of the equipment in case of an emergency.
Appendix E — Water Supply & Distribution Plan E -9
Emergency Response Procedures
Water Quality
Water quality problems occur due to difficulties that can not be managed by the normal
treatment process of the system. Difficulties that might be encountered include source
contamination, a stoppage of treatment, or contamination of the distribution system. An
extensive monitoring program will enable operators to detect contamination in the
distribution system. Unfortunately, it takes as long as several days for the necessary data
to be generated in a laboratory. When the origin of the water contamination is unknown,
each phase of the water supply system should be inspected for possible problems.
When there is reason to believe that the water supply has been contaminated, customers
and health authorities will be contacted without delay. Informing the customers of the
emergency is especially important, as they should be instructed regarding the appropriate
precautions to take.
Recommendation: Update the chlorination equipment in the pump houses so that it is
available in an emergency.
Appendix E — Water Supply & Distribution Plan E -to
Table E -1 Well and Water Quality Data
(1) Expressed as CaCO3 to convert to grains per gallon, multiply by .0584.
Appendix E — Water Supply & Distribution Plan E -11
Well #1
Well #2
Unique Well No.
208794
112205
Year Installed
1968
1975
Aquifer
Jordan
Jordan
Casing Depth, ft.
230
230
Total Depth, ft.
310
291
Casing Diameter, in.
16
16
Static Water Level, ft.
137
128
Drawdown, ft.
7
37
Peak Demand Capacity, gpm
850
850
Pump HP/Type
VT
VT
WATER QUALITY
Results
Well #1 We11#2
Secondary
Standards
Date of Test
4/85
4/85
pH
N/A
7.5
6.5-8.5
Alkalinity, mg/l (1)
210
190
Total Hardness, mg/l (1)
220
200
150-300
Hard
Chloride, mg/I
4.9
3.8
250
Iron, mg/l
<0.01
<0.05
.3
Calcium, mg/l
160
120
Manganese, mg/l
0.04
0.02
.05
Magnesium, mg/l
60
75
Total Solids mg/l
230
220
500
(1) Expressed as CaCO3 to convert to grains per gallon, multiply by .0584.
Appendix E — Water Supply & Distribution Plan E -11
Storms
The effect of storms on water facilities are typically fires, flooding, power outage or
lightning damage to equipment. Structural damage to towers and buildings may also
occur depending upon the type of storm.
In the event of a power outage, storm damage or lightning damage to equipment, the City
will:
1. Determine if emergency generator and Well 1 are operating.
2. Determine available storage volume.
3. Contact Northern States Power Company and get an estimated time for power
restoration.
4. Assess damage to controls and sensing equipment.
Depending on the outcome of steps one and two, Oak Park Heights will take the
following measures:
• obtain an alternative emergency power source
• notify fire department
• operate system manually if necessary
Droughts
Monitoring of the weather can enable one to predict the possibility of a drought
occurring. During drought periods, tower and well levels will be monitored daily. The
monitored information will be used to help determine whether any triggers have been
reached. Furthermore, it is necessary to have emergency plans for limiting water
consumption that can be implemented without delay.
Personnel
In any emergency, it is necessary for the utilities staff to know their respective duties in
resolving the crisis. At the City, all certified water utility operators are trained in
emergency procedures. In addition, it is the City's policy that all operators should attend
continuing education on emergency procedures. In the future, an emergency duty
Appendix E — Water Supply & Distribution Plan E -12
description manual may be developed to clearly communicate specific emergency
procedures to the employees.
Appendix E — Water Supply & Distribution Plan E -13
EMERGENCY PHONE NUMBERS
DNR Permit No 75 -6123
Oak Park Heights Water Utility Staff - First Contact
Not included in this document for privacy reasons. Telephone lists of key personnel are
kept in city water facilities.
Excavation, Water Main Repair
Pete Miller, Miller Contracting ........... ............................... 457 -7870
Well Repair
E.H. Renner & Sons . . ........... ........... ........... ........... ........... 427-6100
Power Outages
Northern States Power ........... ........... ........... ........... ........... 221-4411
Chlorine/Sulfur Dioxide Leak
FeedRite ........................................... ............................... 331 -9100
Oak Park Heights Fire Department ..... ............................... 911
Water Ouality Problems
Department of Natural Resources, Jim Japs ........................ 297 -2835
Pollution Control Agency ................... ............................... 296 -6300 (General
Information)
Minnesota Department of Health ........ ............................... 623 -5000 (General
Information)
City of Stillwater — Water Board
Not included for data privacy reasons.
Minnesota Corrections Facility
Not included for data privacy reasons.
Appendix E— Water Supply & Distribution Plan E -14
Emergency Reporting Information
Oak Park Heights Utility
Use this form to report an emergency that appears to involve water service.
Immediately
contact the Public Works Department. Emergency telephone numbers are attached to this
form.
1. Person reporting emergency Phone no.
Time report
was received Date report was received
2. Location of emergency
Street and houselbuilding number
Other (approximate location, distance from landmark, etc.)
3. Condition at scene [check appropriate box(es)]
_ Escaping Water _ Seepage _
Free- flowing
_ Gushing
_ Flooding _ Roads —
Intersections
_ Property _
Buildings
_ Erosion _ Banks _
Foundations
_ Electrical Power — Interruptions
_ Total loss of power
_ Change in Water Quality _ Taste _
Odor
_ Color _
Clearness
4. Briefly describe the situation, citing any actual or potential damage.
5. Access restrictions, if any
6. Assistance already available (who, what are they doing, etc.)
7. Other comments
Signature of Person Who Filled Out Form
*For use by personnel likely to see or become involved in water system emergencies.
Appendix E — Water Supply & Distribution Plan E -15
CITY OF OAK PARK HEIGHTS
Appendix F - Water Conservation Plan
Water Conservation Plan
Role of Conservation
The water conservation plan for the City of Oak Park Heights is intended to reduce the
demand for water, improve the efficiency of water use, and reduce loss and waste of
water. Conservation is an alternative to developing additional sources of water to meet
peak demands for non - essential uses of water. Reducing the peak use of water will delay
or reduce additional source development and water storage requirements.
The City's conservation goal is to keep total per water use at or below 140 gpcd. The
City has also adopted the conservation goal of keeping the average day to maximum day
ratio below 3.
Demand reduction programs will target uses associated with peak demands, such as
outdoor water practices. By reducing the amount of water used for watering lawns and
plants, Oak Park Heights intends to reduce peak demand and maintain the reduced
demand over the next planning period. Specific program initiatives will be provided in
more detail under the heading Water Conservation Programs.
Future revisions of this report should adjust projected water demands based on the results
of the City's conservation plan. The City's conservation plan will be continuously
evaluated and compared to previous years to measure the success of the programs.
Water Conservation Potential
The City of Oak Park Heights is an established community with a growing population
base. The overall demand on the water system has increased 44% since 1987. In
communities with growing population bases and planned system expansions, water
conservation can play an important role in the management of water resources. Adopting
water efficient practices as a part of the City's Best Management Practices may delay the
development of additional wells as well as expansion to wastewater treatment facilities.
Appendix F — Water Supply & Distribution Plan F -1
Oak Park Heights' water system is in good repair. Therefore, the focus of the water
conservation plan in the future will be on continuing the wise use of water, maintaining
the present condition of the water system, and making repairs to the original distribution
and supply areas as required. Through enforcing building codes, the City can ensure the
retrofit of aging water fixtures with water efficient fixtures. The following is a discussion
of water conservation potential for each of the areas addressed in the Water Supply and
Distribution Plan as well as conservation potential for the various customer classes.
Per Capita Water Use
Per capita water use information is beneficial because it shows who is using the water
and how much water they are using on average. Oak Park Heights' total per capita water
use averages 140 gallons per capita per day (gpcd). Both total and residential per capita
use has remained fairly stable over the last eight years. The City will work with
customers in an effort to keep the per capita use low.
The residential sector will see some decrease in their gallons per capita per day over the
next decade due to the replacement of high water using fixtures that will occur due to the
passage of the 1992 Federal Energy Policy Act.
The total gallons per capita per day is highly dependent upon commercial/industrial
development. The goals described in this plan are realistic.
Water Demand by Customer Category
Residential Customers
Oak Park Heights is in the process of planning for the anticipated growth in the
residential sector due to the growth in new home construction. Clearly it may be
appropriate to create conservation programs that target customer categories. Although
the residential sector comprises approximately 90% of the connections, the City estimates
that residents consume about 53% of the total water pumped each year.
For residential customers, the greatest potential for water savings in the residential sector
is in outdoor watering practices and efficient indoor use. Utilizing water efficient
practices would reduce the total water pumped annually as well as decrease some of the
peak demand periods.
Appendix F — Water Supply & Distribution Plan F -2
Commercial/Institutional Customers
The commercial /institutional sector makes up approximately 10% of the total
connections. Public facilities such as the MN Correctional Facility or Washington
County are good candidates for water conservation programs because they benefit from
the cost savings derived by using less water. Private business usually benefits from
conservation programs if there is sufficient payback potential. It is difficult to target
conservation programs toward commercial users because their uses are usually industry
specific. For instance, a car wash is going to use large amounts of water. If the payback
is sufficient for the owner to invest in technology for recycling water, the owner will
usually undertake the improvement. For businesses, the payback needs to be there in
order to justify the upgrade. Therefore, water conservation efforts for
commercial /institutional customers will focus on plumbing retrofits in public buildings,
water rates and education.
Plumbing Retrofits. Larger public buildings are equipped with commercial toilets that
utilize a Sloan valve for flushing. Most of the toilets use approximately 4.5 gallons
per flush. There are retrofit kits available that save one gallon per flush. The public
facilities' management should consider replacing the valves with a retrofit kit as a
part of the normal maintenance. The valves will conserve water and do not
compromise waste removal.
For buildings that do not have commercial toilets, toilets should be tested on a regular
basis for leaks and repaired when detected. Larger use toilets should be replaced with
1.6 gallon toilets over a period of time.
2. The City is currently reviewing its water rate structure.
3. The City will include education initiatives for business owners and provide them with
resources to seek out about water conservation potential.
Industrial Customers
Oak Park Heights does not have any industrial customers. Oak Park Heights is not
seeking industrial customers that use large amounts of water. All customers will be
encouraged to adopt water efficient technologies as a part of their operations.
Appendix F — Water Supply & Distribution Plan F -3
Unaccounted for Water Use
The average unaccounted for water use was 11% over the last eight years. There is a
good potential to get the unaccounted for water below 10% by metering and better
accounting of estimated uses for flushing, etc.
Seasonal and Peak Water Demands
The greatest potential for water conservation in Oak Park Heights is on seasonal and peak
water demands. Although peak periods, these peaks place an enormous amount of stress
on the system. Through an appropriately targeted water conservation program, Oak Park
Heights intends to reduce the peak demand periods.
Water Conservation Programs
Formal water conservation planning is a relatively new concept for many water utilities,
and the City of Oak Park Heights is no exception. The City of Oak Park Heights has
adopted policies that encourage conservation such as uniform water rates, metering of
customers, and high water rates sprinkling restrictions.
The challenge for conservation program development is targeting uses that can be
reduced through physical change (toilet retrofits) and habitual change (using a broom, not
water to clean sidewalks and driveways). These changes can be encouraged through a
number of different water conservation programs such as education initiatives, retrofit
programs and rebates.
The key for effective water conservation programs in Oak Park Heights is planning. As
Oak Park Heights' population grows, so will the demand for drinking water and
wastewater treatment services. Through appropriate water conservation measures, capital
expenditures for increased demands can be delayed or reduced, which is a large financial
saving for the community.
Successful water conservation programs have specific goal and objectives. The plan
should ensure that the payback is sufficient, it is easy to administer, funding is secured,
and most importantly that it actually conserves water over the long -term.
Appendix F — Water Supply & Distribution Plan F4
The following is a discussion of current conservation measures and conservation
recommendation:
1. Metering: All current and future water users are and will be metered. All large
meters are being repaired or replaced based on AWWA recommendations.
Implementation Plan: In 1999, the City Engineer and Public Works Director
will establish a program for meter calibration and repair. This program will
include large meters (at pumphouses), residential, meters, and commercial
accounts.
2. Water Audits, Leak Detection and Repair: Unaccounted -for water is the
difference between the volume of water sold and the volume of water withdrawn
from the source. Unaccounted for water use has averaged 11 percent from 1988
to 1999. As Oak Park Heights' system ages, the City will continue to maintain
the system and promptly repair leaks. The City will continue to monitor these
losses and work to ensure that they are able to maintain their unaccounted for
water loss at less than 10 %.
Maintaining annual records of the unaccounted -for water allows the City to
monitor the condition of the water system. As the system continues to age, the
City will need to spend more money on leak detection, maintenance and repair.
The rate structure needs to include these future costs. Rates are discussed in more
detail in the next section.
Oak Park Heights currently offers water audits to customers who experience a
large increase over the past billing period. Meters are checked to for leaks and
utility staff offers advice about leak detection and repair.
Implementation Plan: The Water Operator will continue to monitor these losses
and work to ensure that they are able to maintain their unaccounted for water loss
at less than 10 %. The plan will be re- evaluated after the large water metes are
calibrated.
The Water Operator, City Engineer, and Billing Department will meet in 1997 to
establish a strategy to improve the billing system. Issues to evaluate include:
providing water audits for large- volume users who experience a large increase
Appendix F — Water Supply & Distribution Plan F -5
over the past billing period, home water audits, and determining the best
definition of customer categories.
3. Conservation- Oriented Water Rates: The City currently uses a variable rate
system and bills its customers quarterly. A variable rate (cost per gallon
dependent on the amount of use) can be an effective conservation measure. On
the quarterly billing, customers are charged for each 1000 gallons.
Water Rate (per 1000 gal; 50,000 to 100,000 gaVquarter) $ 1.25
Water Rate (per 1000 gal; greater than 100,00 gal /quarter) $ 1.50
The rate system pays for the true cost of supplying, treating and delivering the
water, including maintenance. Future capital expenditures will be financed
through connection charges and assessments.
Implementation Plan: In 1998 and 1999, the Public Works Director will
evaluate alternative rate systems such as increasing block rates, summer
surcharges and a hybrid structure. The Public Works Director will also consider
adopting a small surcharge to fund conservation initiatives.
4. Regulation: The City relies on the following regulations to provide short-term
demand reduction and long -term improvements in water use efficiencies.
A. State and Federal Plumbing Codes: All new homes and retrofits of existing
homes will have water efficient fixtures.
B. Short-term Reduction Procedures: Described in the Emergency Preparedness
Plan.
Implementation Plan: The Public Works Director will annually evaluate the
effectiveness of the new water use restrictions and make recommendations
for improvements.
5. Education and Information Programs: Oak Park Heights is committed to
making a strong effort to educate the public on the benefits of water conservation.
Appendix F — Water Supply & Distribution Plan F-6
Implementation Plan: In 1997, the City will focus its efforts on education
material that is targeted toward user groups and user practices. The City will
evaluate the cost of the program as well. The City should consider the following
education foci:
1. Education targeted to the public on the benefits of water conservation,
focusing on habits and efficient uses of water (this could tie in with the home
audit information i.e. how to check for leaking fixtures, water efficient
fixtures, etc.).
2. Education targeted toward developers, focusing on water efficient plantings
for new developments.
3. Education focused toward commercial users, providing them with resources
to contact for water efficient technologies.
6. Retrofitting Programs: The City Building Inspector will enforce the existing
plumbing codes relating to retrofitting existing water fixtures. As the gallons per
capita per day are low, the City will not pursue a mandated retrofit program for
the residential sector. The payback for a residential program would be too long to
justify the cost. With the enactment of the 1992 Federal Energy Policy Act, all
fixtures available for replacement are water savers. As homeowners gradually
begin to replace aging fixtures or remodel their homes, the high user fixtures will
be replaced by water saving fixtures. The payback for a residential customer will
demand upon fixture use and home water habits. If the residential gallons per
capita dramatically increases and it appears that there may be a good savings
potential for a city wide retrofit program, the City will revisit the possibility of
funding a retrofit program at that time.
Implementation Plan: The City will contact Minnesota Corrections Facility and
Washington County in 1999 to discuss water conservation. Retrofit programs
makes sense for public buildings provided it is a part of the maintenance program,
or regular replacement schedule of parts. Gradually, all higher use fixtures will
be replaced with lower consumption fixtures, and because the change out will
occur as older parts need replacing, there should not be much of a financial on the
public buildings' budgets.
Appendix F — Water Supply & Distribution Plan F -7
1. Water sensors for residential, commercial and industrial sprinkling systems
should be evaluated -- what the payback is, etc.
2. Evaluate the viability of a retrofit program if per capita use warrants it.
7. Pressure Reduction: The City water system has been designed to ensure that
static and residual pressures in the water service area are maintained at an average
of between 40 psi and 90 psi. Users with pressures above 90 psi will be required
to install individual pressure reducing valves at the point of service, unless special
needs dictate. There are currently no customer that have needed to installed
pressure reducing valves in their homes. The only method available to the City to
reduce pressures in an emergency is to lower the water level in the water towers,
This procedure is unacceptable resulting in reductions of available fire protection.
Appendix F — Water Supply & Distribution Plan F -8