Domestic Septage Land Application and Disposal Guidance
Domestic septage is defined as any liquid or solid material removed from a septic tank, cesspool, portable toilet, Type III marine sanitation device or any similar systems that receives only domestic (non-commercial) septage.
Grease trap residues, grit and screenings, and any domestic septage that is combined with commercial or industrial wastes is not considered domestic septage and is regulated by the departmentâ€™s Waste Management Program. For more information on the disposal of non-domestic septage wastes, please contact the Waste Management Program at (605) 773-3153.
Domestic septage may be disposed of in two different ways in South Dakota. The first option is to take the material to a municipal or private wastewater treatment facility where it can be properly treated. The second option is to beneficially reuse the material by land application at non-public contact sites. A non-public contact site is an area where the potential for public exposure is minimal, such as agricultural fields, forests, or mining reclamation sites.
To protect public health and the environment, there are five main requirements the septage must meet to be land applied. These are:
- Pathogen Reduction,
- Vector Attraction Reduction,
- Agronomic application rate, and
- Site restrictions.
Pathogen and Vector Attraction Reduction
Pathogens are disease-causing organisms such as bacteria, viruses, and parasites that may be present in septage. The Pathogen Reduction requirement is used to ensure that any potential pathogens in the septage are reduced to a level that is safe for land application. The next requirement the septage hauler has to meet is a Vector Attraction Reduction (VAR) requirement. Vectors are organisms such as mosquitoes, flies, or rodents that can spread disease by carrying and transferring pathogens. The VAR requirement is used to reduce the potential for attracting these disease-carrying vectors.
There are two options for meeting Pathogen and Vector Attraction Reduction requirements. These are:
- lime (alkali) stabilization or
- injection into the ground or disking into the ground within 6 hours of application.
Lime stabilization involves adding and thoroughly mixing lime (alkali) with each load of septage to ensure that the pH is raised to at least 12 for at least 30 minutes. Usually this requires about 50 lbs of lime per 1,000 gallons of septage. A pH meter must be used to determine whether the pH requirement was met. An operational log and records of the pH readings must be maintained to demonstrate that this requirement has been met for every load that has been land applied.
Septage that is injected into the ground or disked in within 6 hours of application does not have to be lime-stabilized.
The septage must be screened to remove foreign or non-organic objects such as trash or other non-biodegradable objects. Options for this requirement include screening at the site where septage is being collected, screening out the back of the vehicle during land application, or screening using a tank setup. Screenings must be bagged and disposed of at a permitted municipal waste landfill.
Agronomic Application Rate
The septage must be applied at an agronomic rate. The maximum volume of domestic septage that can be land applied in any year depends on the amount of nitrogen required by the crop grown and expected yield. The following equation is provided in the rules to calculate annual domestic septage application rates:
where: AAR = Annual Application Rate (gallons / acre / year)
N = Nitrogen Required by Crop (lbs)
Site restrictions for land applying domestic septage must be met and include minimum time restrictions for harvesting crops, grazing animals, maximum slope and distances from waterbodies, and restricting public access after land application. Site restrictions include:
- Food crops (food or root crops are crops consumed by humans) with harvested parts that touch the soil surface but are totally above the ground, such as melons, tomatoes, etc., shall not be harvested for 14 months after application.
- Root crops with harvested parts below the land surface, such as potatoes, onions, etc., shall not be harvested for 20 months after application if the septage is not disked in and remains on the land surface for four months or more.
- Root crops cannot be harvested for 38 months after application if the septage remains on the land surface for less than four months.
- No crop can be harvested for at least 30 days following application of septage.
- Animals shall not be allowed to graze on the land within 30 days after application.
- Turf cannot be harvested for one year following application of septage if the turf is to be placed on either a lawn, or an area with a high potential for public exposure.
- Public access to land shall be restricted for 30 days after application. This can include remoteness of site, posting with no trespassing signs, and/or fencing.
- Domestic septage may not be applied within 250 feet of any well or residence.
- Domestic septage may not be applied to land with a slope greater than 6%.
- Domestic septage may be applied to land with a slope between 3% and 6% provided 85% of the area is covered with vegetation.
- Domestic septage may not be applied within 100 feet of any surface water or within 100 feet of drainages.
Exceptions to Site Restrictions
When septage is lime stabilized prior to application, the restrictions on animal grazing, turf use, and public access no longer apply to the site. All other site restrictions still apply.
Records of domestic septage disposal must be maintained that show that the domestic septage hauler is meeting all of these requirements. These records must be maintained for a minimum of five (5) years. Required records include:
- Location of the application site (street address, latitude/longitude, etc);
- Number of acres on which septage is applied at each site;
- Date and time of each application;
- Nitrogen requirement of the crop or vegetation grown on each site for each calendar year;
- Gallons of septage applied to each site;
- Description of pathogen and vector attraction reduction measures used; and
- Required certification statement.
These rules and regulations became effective in 1993. In 2001, South Dakota was delegated to administer and enforce the septage program. The Department of Environment and Natural Resources will conduct routine inspections and may require you to submit a copy of your records for further investigation. If you have questions about the requirements in this letter or would like more information, please contact Tina McFarling, South Dakota Biosolids Coordinator, at (605) 773-3351.