1997-10-21 MDH Review
m
Minnesota Department of Health
121 East Seventh Place
P.O. Box 64975
S1. Paul, MN 55164-0975
October 21, 1997
Mr. Garrison Hale
City Administrator
5975 Main Avenue Northeast
Albertville, Minnesota 55301
Dear Mr. Hale:
Minnesota Department of Health (MDH) staff have reviewed the revised Environmental
Assessment Worksheet (EA W) for the Cedar Creek golf course and residential development,
Wright County, Minnesota. We understand that the proposed project is a golf course,
clubhouse, and a residential development with townhome units and single-family residential
lots. Required concomitant development includes streets, stormwater and erosion controls,
and utilities including water and sewage disposal.
1. Any new well must be installed by a licensed well contractor and meet all other
requirements of Minnesota Rules, Chapter 4725 (rules regulating Wells and Borings, also
termed the Well Code).
2. The Well Code requires that all wells be protected from possible backflow or back-
siphoning of a contaminant into the well. To prevent this, irrigation wells must have an
approved backflow prevention device if the well will be used for application of
agricultural chemicals (chemigation). No cross-connection is allowed between an
irrigation well and a water supply well unless an approved backflow prevention device is
maintained on the system. If any well, including an irrigation well, will be used to fill a
tank for mixing of an agricultural chemical (e.g. a pesticide), the well must either be
protected with a backflow prevention device or maintain an air gap or separation of at
least twice the pipe diameter. For further information, please contact Ronald Thompson at
612/215-0831.
TOO: (612) 623-5522 (Twin Cities) 1-800-627-3529 (Greater Minnesota)
An Equal Opportunity Employer
,.
Mr. Garrison Hale
October 21, 1997
Page 2
3. Minnesota Statutes, section 1031.205 prohibits the placement of buried sewers, or any
other regulated source of contamination, any closer to an existing water supply well
(active or unused, unsealed) than the distances prescribed by the Well Code.
The Well Code specifies the following setback distances between water supply wells and
buried sewers, including building drains connected to the building sewer:
50 feet: A minimum setback distance of at least 50 feet must be maintained between a
well and a buried sewer if the sewer:
a. is a collector or municipal sewer;
b. is pressurized and serves more than a single-family residence;
c. is open-jointed; or
d. is constructed of materials that do not meet the material, installation and testing
requirements in the Minnesota Plumbing Code.
20 feet: The 50-foot separation distance may be reduced to 20 feet if the sewer meets the
material, installation and testing requirements in the Minnesota Plumbing Code, AND it is:
a. a buried, gravity sewer that serves a single-family residence or a single facility such as
a business, church, school, or single commercial property. (This does not include
collectors or municipal sewers); or
b. a buried, pressurized sewer that serves a single-family residence.
4. The Well Code specifies that the setback distance between water supply wells and
stormwater pipes or conduits must be 20 feet if the pipe is 12 inches in diameter or
greater; there is no setback distance requirement if the pipe is less than 12 inches in
diameter. If the pipe carries sewage or sewage can back up in the pipe, the piping is
considered a sewer, not a stormwater drain.
5. Please note that the Minnesota Plumbing Code requires that a buried sewer or drain be
located at least 10 feet from a buried water service line, or if this distance cannot be
maintained, the installation and materials must comply with Minnesota Rules Chapter
4715.1710, subp. 2 (Minnesota Plumbing Code). Questions should be directed to the local
plumbing administrative authority or the state plumbing regulation program at
612/215-0836.
Mr. Garrison Hale
October 21, 1997
Page 3
6. To ensure that the isolation distances will be met, we recommend that a field well
inventory be performed to actively determine in advance the locations of all existing
water supply wells (active or unused, unsealed), especially any wells along the routes of
the new sewer lines or any sewer lines to be replaced, as well as along the routes of any
large diameter stormwater pipes. Particular attention should be made in the areas shown
on air photos, old maps, etc. where any farmsteads have been located on this property, as
well as along property boundaries where wells on adjacent properties may still exist.
Once a well is sealed by a licensed well contractor in accordance with requirements of the
Well Code, the isolation distance is no longer an issue.
Thank you for the opportunity to review this EA W. If you have questions or need further
information, please contact Betty Wheeler at 612/215-0807.
DWW:BJW:sig
cc: James Nye
Ronald Thompson
Betty Wheeler
Curtis Wunderlich