This page lists sources of contamination and the well isolation distances required from those sources by state codes. The Michigan Department of Environment, Great Lakes, and Energy and local health departments have authority to issue deviations from these minimum isolation distances on a case by case basis. Criteria for issuance of deviations are set forth in R 325.1613 of the Rules for Part 127, and R 325.10809 of the Rules for Act 399.
The listed isolation distances are minimum distances. The regulatory agency has the authority to increase the minimum isolation distance based on factors such as: geology, groundwater flow direction, well construction, type of contaminant, etc.
|
Contamination source |
Required minimum isolation distance (feet) |
Required minimum isolation distance (feet) |
Required minimum isolation distance (feet) |
|---|---|---|---|
|
Agricultural chemical or fertilizer storage or preparation area |
150 |
800 |
2000 |
|
Animal waste lagoon or manure storage |
*150 |
800 |
2000 |
|
Animal or poultry yard |
50 |
75 |
200 |
|
Brine wells or injection well |
**150 |
**800 |
**2000 |
|
Building or projection thereof |
3 |
3 |
3 |
|
Cemetery and graves |
**50 |
**75 |
**200 |
|
Cesspool |
50 |
75 |
200 |
|
Chemical storage |
150 |
800 |
2000 |
|
Contaminant plumes (Part 201, LUST sites, etc.) |
**300 |
**800 |
**2000 |
|
Drainfield |
50 |
75 |
200 |
|
Drywell |
50 |
75 |
200 |
|
Footing drain |
10 |
10 |
10 |
|
Fuel chemical storage tanks - underground or abovegrade and associated piping Depot tank farm |
300 |
800 |
2000 |
|
Fuel chemical storage tanks - underground or abovegrade and associated piping 1,1000 gallon or larger, without secondary containment |
300 |
800 |
2000 |
|
Fuel chemical storage tanks - underground or abovegrade and associated piping 1,100 gallon or larger with secondary containment |
50 |
800 |
2000 |
|
Fuel chemical storage tanks - underground or abovegrade and associated piping less than 1,000 gallon that store motor or heating fuel for noncommercial purpose or consumptive use on premises where fuel is stored |
50 |
800 |
2000 |
|
Fuel chemical storage tanks - underground or abovegrade and associated piping less than 1,100 gallon that store motor fuel for commercial purpose |
*50 |
800 |
2000 |
|
Fuel chemical storage tanks - underground or abovegrade and associated piping located in a basement, regardless of size |
*50 |
800 |
2000 |
|
Grease trap |
50 |
*75 |
*200 |
|
Kennel |
50 |
*75 |
*200 |
|
Landfill or dump sites (active or inactive) |
800 |
800 |
2000 |
|
Liquid waste draining into the soil |
50 |
*75 |
200 |
|
Metering station for pipeline |
*300 |
*300 |
*300 |
|
Municipal wastewater effluent or sludge disposal area (land surface application or subsurface injection) |
300 |
800 |
2000 |
|
Municipal wastewater lagoon |
*300 |
800 |
2000 |
|
Oil or gas well |
300 |
300 |
300 |
|
Other wastewater handling or disposal unit |
50 |
*75 |
*200 |
|
Petroleum product processing or bulk storage |
300 |
800 |
2000 |
|
Pipeline for gas, oil |
*300 |
*300 |
*300 |
|
Privy/outhouse |
50 |
75 |
200 |
|
Seepage pit |
50 |
75 |
200 |
|
Septic tank |
50 |
75 |
200 |
|
Septage waste (land application area) |
800 |
800 |
2000 |
|
Sewage holding tank |
50 |
*75 |
*200 |
|
Sewage lagoon serving a single family dwelling |
50 |
75 |
200 |
|
Sewage lagoon effluent - land application area |
50 |
800 |
2000 |
|
Sewage or liquid waste draining into soil |
50 |
*75 |
*200 |
|
Sewage pump chamber, transfer station, or lift station |
50 |
75 |
200 |
|
Sewers Buried gravity sewer (sanitary or storm) - service weight or heavier ductile-iron or cast iron, or schedule 40 PVC, all with watertight joints |
10 |
75 |
200 |
|
Sewers Buried pressure sewer (sanitary or storm) - watertight joints (pressure tested after installation to 100psi), equivalent to schedule 40 or SDR 21, and meets or exceeds ASTM specifications D1785-91 or D2241-89 |
10 (by written deviation only) |
75 |
200 |
|
Sewers Buried gravity or pressure (sanitary or storm), constructed of materials not meeting the specifications listed in the two categories above, or the materials are unknown |
50 |
75 |
200 |
|
Sump pit Receiving other than household waste (footing drain, roof drain, etc.) |
10 |
10 |
10 |
|
Sump pit Receiving household waste (laundry, softener backwash, sink waste, etc.) |
50 |
75 |
200 |
|
Surface water (lake, river, stream, pond, ditch, etc.) |
10 |
75 |
200 |
|
Unfilled space below ground surface (except an approved basement, basement offset, or crawl space beneath single family dwelling) |
10 |
10 |
10 |
*For the isolation distances marked with a single asterisk, the isolation distance is for a source of contamination which is not specifically listed in the rules. However, the source of contamination is interpreted as belonging in a general contamination source group (example - a sewage holding tank is the same as a septic tank) which is listed in the rules, and therefore, the isolation distance listed here is required.
**For the isolation distances marked with a double asterisk, the isolation distance is from a source of contamination which is not specifically named in the rules. However, the Michigan Department of Environment, Great Lakes, and Energy has established a recommended isolation distance based on the contaminant involved, the risk to public health, and other factors. Under the general authority of a health officer's responsibility to protect the public health, health officers may modify this recommended isolation distance, either increasing or decreasing it, on a case by case basis.
