There are other considerations when installing an SSTS for facilities serving more than 3 single family home or establishments having a flow greater than 2500 gallons per day.
A system that is designed to manage a flow of greater than 10,000 gallons per day is reviewed and permitted by the MPCA. Local units of government typically review designs and issue construction permits for SSTS designed for 10,000 gallons per day or less. The Minnesota Department of Health (or designated local health department) reviews and approves designs for systems that serve health care facilities.
There are certain criteria that need to be met when designing an LSTS. Flow determination, site evaluation, treatment, drainfield sizing, septic tank sizing, and sewer system design are addressed in these documents.
- Design Guidance for Large Subsurface Wastewater Treatment Systems (LSTS) (wq-wwprm8-01)
- High Rate Soil Absorption System (HSRS) Final Report (file size = 10.7 MB)
- Department of Labor and Industry Plan Review Application
- Municipal Large Subsurface Treatment System Application -- For permit for the land application of domestic wastewater using a large subsurface sewage treatment system
Permits issued by the MPCA include monitoring and reporting requirements as well as proper operation and maintenance of the system. For more information, please refer to the following fact sheets:
- NPDES/SDS Permit Information
- Transfer of MPCA Wastewater Permits: A Homeowner's Association Guide
- Water-quality Permit Requirements for Wastewater Discharges to Ground Surface and Subsurface
All sizes of Type IV SSTS (systems with advanced treatment), and all SSTS with a flow of 2,501 gallons per day to 10,000 gallons per day need to be designed by an Advanced Design business with some components needing to be designed by AELSLAGID professionals. Below are Prescriptive Standards and Design Guidance that Advanced Designers must follow in designing the above mentioned systems.
- Subsurface Sewage Treatment Systems: Prescriptive designs and design guidance for advanced designers (wq-wwists4-44)
- Single Pass Sand Filters - Recommended Standards and Guidance (RSG) Document (wq-wwists4-42)
- Recirculating Sand Filters - Recommended Standards and Guidance (RSG) Document (wq-wwists-41)
Class V systems are defined as:
Business Septic Systems are Class V Injection Wells, regulated by the state ISTS rules and US EPA from their Chicago office.
All Class V wells need to be inventoried with EPA. Below is the link to EPA's registration form and instructions on how to complete it:
- Underground Injection Well (UIC) Class V Inventory Form
- Instructions for Completing the Class V Inventory Form
Two kinds of Class V wells are banned nationwide; those at vehicle maintenance shops and community cesspools. New ones are prohibited, and those in wellhead protection areas were required to be closed in January 2007.
- EPA Bans Two Types of Waste Disposal Systems — fact sheet
Existing Class V wells at vehicle maintenance shops not located within wellhead protection areas do not need to close according to EPA’s rules. They do need to VERY CLOSELY scrutinize what is going down those wells. All hazardous waste in the shops must be managed in accordance with Minnesota’s Hazardous Waste requirements.
If your vehicle maintenance shop can’t discharge to city sewer or to a septic system (Class V well), what can you do?
- Floor drains, Separators and Traps, and Holding Tanks (w-hw4-18)
- Recycling Petroleum Products from Auto Dealerships
There are other types of business septic systems and EPA has requirements for them as well.
If you have questions about the EPA program, it’s best to contact the EPA:
Federal UIC - Class V Contacts:
Undersewered areas have inadequate wastewater treatment, where existing wastewater treatment methods are not adequate to protect public health or the environment. The situations range from failing individual systems to cities with inadequate collection and treatment infrastructure.
Unsewered areas do not have centralized wastewater collection and treatment, where wastewater collection is not done through a large sewer system.
- Small community wastewater needs in Minnesota (2008)
Report contains three main sections: summary of accomplishments made by 111 small communities during the past 12 years; identification of small communities' current wastewater needs; a strategy to work more proactively with small communities to resolve their wastewater issues. The survey results identified over 1,025 small communities with wastewater needs. Our goal is to eliminate 106 unpermitted surface discharges from both community and individual "straight pipe" discharges in Minnesota. (wq-wwtp1-06)
- Small community wastewater needs in Minnesota - A strategy for progress
- Small community wastewater treatment program start-up assistance and management evaluation (wq-wwtp1-09)
- U.S. EPA Decentralized Waste Water Systems
There are other state rules relating central sewer systems to SSTS, including:
- Underground Waters MN Rule Chapter 7060.0600 Subp. 5
- Shoreland Act and Flood Plain Management MN Rule Chapter 6120, 3400 subp. 3.A.
- State Plumbing Code MN Rule Chapter 4715.0310
- Minnesota Board of Architecture, Engineering, Land Surveying, Landscape Architecture, Geoscience and Interior Design