HomeMy WebLinkAbout1997-02-04 MN SWCD Ltr to River States PropertiesI
MINNESOTA
SOIL AND WATER CONSERVATION DISTRICTS
11 ( �`
February 4, 1997
Mr. J. R. (Dick) Stockstead
River States Properties, Inc.
2600 Wild Pines Lane
Stillwater, MN 55082
RE: Proposed Kangaroo Storage Facility - Kern Center, Baytown Township
Dear Mr. Stockstead:
My comments are as follows:
AN EQUAL OPPORTUNITY EMPLOYER
WASHINGTON SOIL AND WATER
CONSERVATION DISTRICT
1825 Curve Crest Blvd„ Room 101
Stillwater, MN 55082
(612) 439.6361 Fax: (612) 351 -7606
At your request, I Have reviewed the revised (January 14, 1997) grading and drainage plan for the proposed
Kangaroo Storage Facility to be located in the Kern Center in Baytown Township. Since the overall Kern
Center development was a permitte4 project from Valley Branch Watershed District, no additional permit is
needed from them at this time. However, what is confusing is that while the Kern Center is legally within the
Valley Branch Watershed District, the permanent stormwater facility within the development drains to the
Brown's Creek Watershed. Since Washington County recently took on planning and implementation authority
for Brown's Creek and contracted with our agency for that work, our review is for consistency with the Brown's
Creek Watershed Management Plan and other applicable state, and local rules.
1) Since the total area to be disturbed is in excess of five areas, an NPDES (National Pollution Discharge
Elimination System) permit is required. A permit application can be obtained from the MPCA by calling 296 -
7219.
2) As we previously discussed, a temporary sediment basin is being provided, however, based upon the
revised plan submitted, the basin appears to be only 6,500 cubic feet in size. NPDES permits require 1,800
cubic feet for every acre of disturbance. This would require a temporary sediment basin to be approximately
10,800 cubic feet in volume for the nearly six acres of disturbance that will occur for this project. I believe
there is adequate room to expand the proposed basin to the north and not interfere with the septic system or
building four.
3) Since the purpose of the temporary sediment basin is to filter out course grain sediments during
construction, it is vital that as much of the site drain to this temporary basin during the construction phase. This
may require a temporary diversion berm along the east edge of the site or could be accommodated by other
temporary grading operations to direct runoff to the southeast corner of the site.
Mr. J. R. (Dick) Stockstead
February 4, 1997
Page Two
4) The temporary sediment basin needs to have an armored inlet and outlet such as rip -rap. The outlet
needs to allow water to get to the existing road ditch without causing an erosion problem. Also, the outlet must
be moved to the northern edge of the basin to prevent short circuiting of the runoff water.
5) The site should have a graveled construction entrance to reduce the tracking of sediment off -site.
Construction access should then be restricted to this one location.
6) Silt fence should be installed prior to any construction activities and should be placed along the contour
as much as possible.
7) On the "Site Plan" from the reduced copies of drawings most recently submitted it states, `Existing
Woods Line To Remain ", yet the grading plan shows substantial grading and a silt fence in this area. If trees are
to be removed, the site plan should probably more accurately reflect the loss of woody plants. Also, if oaks
exist within the tree line, any grading or action that could wound a tree should be avoided from April to June to
prevent the spread of Oak Wilt disease.
8) Finally, it is recommend that an overall construction sequencing plan be prepared to show what work
will be done when and b y whom. i have attached an example from MPCA on the timing and installation of
construction site BMPs for your use.
I hope these comments assist you with your final design. I would be happy to rereview any changes that are
made prior to final approval If you have any questions, please feel free to call me at 439 -6361.
Sincerely,
Mark J. Doneux
Water Resource Specialist
enc: MPCA m Example of Timing and Installation of BMP's for Erosion and Sediment Control
cc: Dennis O'Donnel, Washington County H.E.L.M. (w /o enc.)
Randy Peterson, Barr Engineering Co., (Valley Branch Watershed District) (w /o enc.)
Pat St. Claire, Clerk, Baytown Township (w /o enc.)
file: Brown's Creek Watershed - Kern Center (w /o enc.)
Baytown Township (w /o enc.)
C:IMSOFFICEIWINWORDIMJDILGUIBYT \O2O4STOC.DOC