3,000 Gallon Per Day or Less No-discharge Permit Exemption for Domestic Wastewater Design Guidance - PUB1319

Certain small, no-discharge, domestic wastewater treatment facilities can be eligible for an exemption established in regulation for construction and operating permits, and therefore are not required to obtain approval from the Missouri Department of Natural Resources. The permit exemption applies to facilities that satisfy the following criteria:

• Generate domestic wastewater only (i.e., bathroom and toilet wastewater, residential laundry wastewater, residential kitchen wastewater, etc.)
• At a maximum rate of 3,000 gallons per day or less and
• Use a no-discharge earthen basin (i.e., lagoon) to hold the wastewater, which is followed by: 
  • A surface land irrigation method located within the same operating location
  • A subsurface soil dispersal system, commonly called a septic field, or
  • Pumping and hauling the wastewater to a permitted treatment facility that is able to accept the specific waste 

At no time may the wastewater be discharged from the operating location’s property or to surface or groundwater of the state.

The purpose of this publication is to explain eligibility requirements to meet the 3,000 gallons per day or less no-discharge lagoon exemption, established in Code of State Regulations 10 CSR 20-6.015(3)(B)6. In order to meet the requirements of the permit exemption, all no-discharge lagoons and any soil-based treatment systems must be designed by an individual who is a professional engineer licensed in Missouri, as described in Missouri Revised Statutes section 644.051, RSMo, and that design must follow the criteria contained in 10 CSR 20-8.

The no-discharge permit exemption does not excuse any facility or person from complying with the Missouri Clean Water Law or any other federal, state or local laws. It is the facility owner’s responsibility to demonstrate to the department that the system is and should be exempt.

Regardless if the no-discharge lagoon is exempt from a construction or operating permits,it will remain under the department’s jurisdictional authority throughout its lifespan. As described in 10 CSR 20-6.015(2)(B), nothing shall prevent the department from taking action to ensure facilities do not discharge into surface or groundwater of the state, including requiring construction or operating permits for facilities that were otherwise exempt. The department may require permits to correct noncompliance, or when construction or operation and maintenance practices are not adequate.

This publication does not apply to facilities that fall under the jurisdiction of the Missouri Department of Health and Senior Services, On-site Wastewater Treatment Program or a local onsite wastewater authority, commonly the local health department. The department recommends reviewing the publication, Who Regulates Domestic Wastewater in Missouri? - PUB1296, for guidance in determining jurisdictional responsibility.

What is Domestic Wastewater?

As defined in 10 CSR 20-2.010(26), domestic wastewater is “wastewater (i.e., human sewage) originating primarily from the sanitary conveniences of residences, commercial buildings, factories, and institutions, including any water which may have infiltrated the sewers. Domestic wastewater excludes stormwater, animal waste, process waste, and other similar waste.”

What is a “No-discharge” Wastewater System?

As defined in 10 CSR 20-2.010(50), a no-discharge facility is “a facility designed, constructed, and operated to hold or irrigate, or otherwise dispose without discharge to surface or subsurface waters of the state, all process wastes and associated stormwater flows except for discharges that are caused by catastrophic and chronic storm events; any basin is sealed in accordance with 10 CSR 20-8, Minimum Design Standards; and no subsurface releases exist in violation of 10 CSR 20-7.015, Effluent Regulations, or section 577.155, RSMo.”

For the purpose of this publication, a no-discharge wastewater system is one that is designed, constructed, operated and maintained to hold or irrigate/ disperse domestic wastewater without discharging to surface or groundwater.

When is an Exemption Possible?

As described above, an exemption from a construction or operating permit is possible when a facility satisfies the following criteria:

1. Generate 3,000 gallons per day or less of domestic wastewater only that is
2. Held within a no-discharge lagoon (earthen basin), followed by
3. Onsite surface land irrigation, subsurface soil dispersal or pumped and hauled to a permitted facility, so that no discharges occur from the operating location.

While strongly recommended, it is not necessary for those systems to have onsite irrigation equipment, nor are they required to have a contract with a pumper-hauler or approval from the receiving facility, to qualify for this exemption.

No-discharge Lagoon

When designing a no-discharge lagoon, the licensed professional engineer should calculate the maximum gallons of domestic wastewater generated per day, to ensure it satisfies the exemption. The licensed professional engineer also should calculate whether the lagoon has sufficient storage volume to store the wastewater when the soils are saturated, frozen or snow-covered. The calculations to determine the maximum gallons of domestic wastewater generated per day at a facility must follow the criteria contained in the department's Wastewater Guidelines and Standards Document - PUB2754, Table 1-1. Minimum Design Loadings. The exemption is not based on a weekly, monthly or yearly average.

All lagoons, including no-discharge lagoons that serve anything other than a single-family residence, are the jurisdictional responsibility of the Missouri Department of Natural Resources throughout their lifespan, even if they are exempt from construction or operating permits. As described in 19 CSR 20-3.060(6)(D), the Missouri Department of Health and Senior Services, On-site Wastewater Treatment Program or the local on-site wastewater authority have jurisdictional responsibility for a single-family lagoon that serves no more than one single-family residence, and therefore does not qualify for the no-discharge lagoon exemption. The department recommends contacting the Missouri Department of Health and Senior Services, Onsite Wastewater Treatment Program or the local onsite wastewater authority for specific design and permitting requirements.

Land Application

A surface land irrigation system or a subsurface soil dispersal system must be designed by a professional engineer licensed in Missouri and must handle lagoon effluent in such a manner that there is no discharge to surface or groundwater of the state. Typical types of surface irrigation systems used for domestic wastewater include, but are not limited to, portable pump(s) with movable sprinklers and pump(s) with solid-set sprinklers. Domestic wastewater should only be surface-land irrigated when the soils allow and not when the soils are saturated, frozen or snow-covered. Typical subsurface soil dispersal systems include conventional gravity-pipe and gravel systems, conventional gravity-gravelless pipe systems, Low Pressure Pipe (LPP) systems and drip irrigation systems.

The department recommends if the facility’s accumulated maximum daily flows of domestic wastewater for the entire facility under the same common promotional plan or within the same operating location is 3,000 gallons per day or less, and they propose to use a subsurface soil dispersal system following a no-discharge lagoon, they should consider closing the lagoon and contacting the Missouri Department of Health and Senior Services, Onsite Wastewater Treatment Program or the local onsite wastewater authority for specific design and permitting requirements for an onsite wastewater treatment system under their jurisdiction.

When Does a No-discharge Lagoon Require Construction or Operating Permits? 

Department-issued construction permits are required for any no-discharge lagoon when the accumulated maximum gallons of domestic wastewater operated under the same common promotional plan or within the same operating location are more than 3,000 gallons per day. An operating permit is required when those lagoons are followed by either surface land irrigation or a subsurface soil dispersal system. However, an operating permit is not required when the wastewater from those lagoons are pumped and hauled to a permitted treatment or disposal facility, provided the owner has a written contract with the pumper-hauler and approval from the receiving facility.

Summary

If a no-discharge domestic wastewater lagoon receiving 3,000 gallons per day or less is followed by either a surface land irrigation system, a subsurface soil dispersal system or is pumped and hauled to a permitted facility, it may be considered exempt by regulation and is not required to receive a construction or operating permit. It is the facility owner’s responsibility to demonstrate to the department that the system is exempt.

As required by section 644.051, RSMo, whether or not a construction permit is needed, all no-discharge lagoons, surface land application systems and subsurface soil dispersal systems must be designed by a professional engineer licensed in Missouri, and that design must follow the criteria contained in 10 CSR 20-8.

As described in 10 CSR 20-6.015(2)(B), nothing shall prevent the department from taking action to ensure facilities do not discharge into surface or groundwater, including requiring permits for facilities that were normally exempt. The department may require permits to correct noncompliance, or when it is determined that construction, operation or maintenance practices are not adequate, or for protecting public health and the environment.

The no-discharge permit exemption does not excuse any facility or person from complying with or from liability for violations of the Missouri Clean Water Law and regulations or any other federal, state or local laws. Failure to operate and maintain the facility as a no-discharge wastewater treatment system may be considered a violation of the Missouri Clean Water Law and its regulations resulting in enforcement action.