3,000 GALLON PER DAY OR LESS NO-DISCHARGE PERMIT EXEMPTION FOR DOMESTIC WASTEWATER DESIGN GUIDANCE

Water Protection Program fact sheet
04/2015
Division of Environmental Quality Director: Leanne Tippett Mosby
PUB1319

Some small, no-discharge, domestic wastewater treatment facilities can be eligible for a permit exemption and therefore not require Department of Natural Resources approval. The exemption is available for facilities that generate only domestic wastewater (bathroom and toilet waste, residential laundry waste, residential kitchen waste, etc.) at a rate of 3,000 gallons per day or less that is held in an earthen basin (lagoon) followed by onsite surface land application. At no time may the domestic wastewater be discharged from the operating location (property) or into surface or groundwater.

This fact sheet gives guidance that should help satisfy the criteria for the 3,000 gallons per day or less no-discharge lagoon exemption when followed by onsite surface land application. The department strongly recommends working with a registered professional engineer and using 10 CSR 20-8.020, Design of Small Sewage Works for the specific design requirements not included as part of this fact sheet to ensure the no-discharge wastewater treatment system meets or exceeds the requirements of the exemption.

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 construction or operating permits for facilities that were previously exempt. The department may require permits to correct noncompliance, or when construction or operating practices are not adequate.

The no-discharge permit exemption does not excuse any facility or person from complying with the Missouri Clean Water Law or any other state or local laws. The burden of proof for the exemption is on the owner of the facility and it is their responsibility to demonstrate to the department that the system is and should be exempt from permitting requirements.

What is a “no-discharge” wastewater system?
For the purpose of this fact sheet, a no-discharge wastewater system is one that is designed, constructed, operated, and maintained to hold and/or irrigate domestic wastewater without discharging to surface or groundwater.

What is the definition of domestic wastewater?
Section 701.025 (12), RSMo, Definitions, defines “sewage” or “domestic sewage” as “…Human excreta and wastewater, including bath and toilet waste, residential laundry waste, residential kitchen waste and other similar waste from household or establishment appurtenances.”

For the purpose of this fact sheet “wastewater” or “domestic wastewater” shall be defined the same as “sewage” or “domestic sewage.”

When is an exemption possible?
An exemption from a construction or operating permit may be possible when a facility generates 3,000 gallons per day or less of domestic wastewater that is held within a no-discharge lagoon (earthen basin), followed by onsite surface land application operated so that no discharges occur.  However, the department may determine the operating practices are not adequate and a construction or operating permit is necessary to protect public health and the environment.

Who has regulatory jurisdiction over no-discharge lagoons?
No-discharge lagoons are the jurisdictional responsibility of the department until it is properly closed.

When does a no-discharge lagoon require construction and operating permits and when do they not?
As of Jan. 12, 2015, the construction of all new 3,000 gallon per day or less no-discharge lagoons where the wastewater is to be pumped and hauled to a permitted facility are required to receive construction permits from the department. Subsequent operating permits are also required for these no-discharge lagoons as well.

All 3,000 gallon per day or less no-discharge lagoons in existence prior to Jan. 12, 2015, where the wastewater has been pumped and hauled to a permitted facility, shall be reviewed on a case-by-case basis to determine if construction or operating permits are required.

All 3,000 gallon per day or less no-discharge lagoons followed by surface land application that are operated as such, may be considered exempt by rule, unless it is determined by the department the operating practices are not adequate and that an operating permit is necessary to protect public health and the environment.

All no-discharge lagoons should be designed and constructed in accordance with Chapter 8 Design Guidance regardless of whether or not they require a construction permit. A copy of the design guidance is available on the Missouri Secretary of State’s website at http://www.sos.mo.gov/adrules/csr/current/10csr/10c20-8.pdf.

Construction and operating permits from the department shall be required when the accumulated maximum daily flows of domestic wastewater for a facility under the same common promotional plan or operating location are greater than 3,000 gallons per day.

Construction and operating permits are required from the department to satisfy 10 CSR 20-6.030 (1)(C) 6 for centralized wastewater collection and treatment systems for a subdivision. To satisfy that section, all requirements of the Missouri Clean Water Law and regulations, including continuing authority, in accordance with 10 CSR 20-6.010, must be established prior to the sale, lease, or the commencement of construction by the developer or any individual.

Construction and operating permits from the department shall be required for all 3,000 gallons per day or less no-discharge lagoons when followed by subsurface soil dispersal (absorption) system.

A single family lagoon serving an individual residence on an individual lot is the jurisdictional responsibility of the Missouri Department of Health and Senior Services’ Onsite Wastewater Treatment Program or the local administrative authority (commonly the local health department) and does not qualify for the no-discharge lagoon exemption. The Department of Natural Resources recommends contacting the Department of Health and Senior Services’ Onsite Wastewater Treatment Program or the local administrative authority for specific design and permitting requirements.

Basic No-discharge Lagoon Design Guidance
This fact sheet should only be used as a guide and is not intended to satisfy specific design criteria. The Department of Natural Resources strongly recommends working with a professional engineer registered in Missouri and use 10 CSR 20-8.020, Design of Small Sewage Works, for specific design requirements not included as part of this fact sheet to ensure the no-discharge lagoon can be considered exempt.

The no-discharge lagoon should be sited with a clear sweep of the surrounding area by prevailing winds. Heavy timber should be removed to enhance wind action, to prevent shading, and to minimize root intrusion. Avoid steeply sloping areas. Specific set-back distances can be found in 10 CSR 20-8.020, Design of Small Sewage Works.

In order to size the lagoon, the maximum amount of domestic wastewater expected to be produced per day for the facility must be determined. The maximum daily design flows expected from single family residences, apartments, hotels, restaurants or other facilities can be determined by using Table 1 of 10 CSR 20-8.020 (11)(B)3.

The no-discharge lagoon sizes and dimensions shown in Table 1 (below) includes storage and rainfall for the estimated maximum daily flows listed along with the approximate land area required for surface land application. Table 1 uses 3:1 berm side slopes; refer to 10 CSR 20-8.020, Design of Small Sewage Works, for specific design and construction criteria.

There must be sufficient storage volume in the lagoon to store wastewater when the soil is frozen or snow covered during winter or during extended periods of saturated soil conditions. The storage volume between the 2 foot operating level and the 5 foot level should be at least 60 days in southern Missouri to 120 days in northern Missouri. Table 1 below is generally adequate to achieve these storage periods except that the lagoons should be constructed a foot deeper, or to a 6-foot operating depth in the northern third of Missouri to accommodate a 120 day storage period. The Department of Natural Resources strongly recommends working with a Missouri-registered professional engineer to ensure sufficient storage throughout the year.

The total lagoon depth must include 2 feet of freeboard above the 5 foot operating level for a total lagoon depth of 7 feet. Lagoons in the northern one-third of Missouri should have a total depth of 8 feet.

Additional storage must be provided for the one-in-ten year rainfall minus evaporation for 90 days. This volume of water can be contained using one foot of the two feet of freeboard.

Table 1*

LAGOON DIMENSIONS (L X W) (Using a side slope of 3:1)

FLOW (GPD) 300

SQUARE LAGOON

RECTANGLE LAGOON

LAND

Bottom

Berm Top

Bottom

Berm Top

APPLICATION AREA (SQ. FT.)

LB x WB

LT x WT

LB x WB

LT x WT

14 x 14

56 x 56

17 x10

59 x 52

11,200

600

28 x 28

70 x 70

38 x 20

80 x 62

18,500

900

39 x 39

81 x 81

50 x 30

93 x 72

25,810

1200

49 x 49

91 x 91

73 x 30

115 x 72

33,130

1500

57 x 57

99 x 99

86 x 35

128 x 77

40,450

1800

64 x 64

106 x 106

97 x 40

139 x 82

47,770

2100

71 x 71

113 x 113

118 x 40

160 x 82

55,100

2400

77 x 77

119 x 119

125 x 45

167 x 87

62,410

2700

83 x 83

125 x 125

138 x 47

180 x 89

69,730

3000

89 x 89

131 x 131

146 x 51

188 x 93

77,050

*The dimensions presented in Table 1 are for 7 foot deep lagoons.


The Department of Natural Resources strongly recommends the following for a no-discharge lagoon:

As described in 10 CSR 20-6.015 (2)(B), if the Department of Natural Resources determines that construction or operating practices for the no-discharge lagoon are not adequate, construction and/or operating permits may be required to ensure the facility is protective of the environment and public health.

Basic Land Application Guidance
If a proposed 3,000 gallon per day or less no-discharge lagoon is followed by onsite surface land application (and is operated as such), then it is exempt by rule and may not require construction and operating permits. The information stated within this portion of the fact sheet should only be used as a guide with respect to surface land application systems. The Department of Natural Resources strongly recommends working with someone who is registered as a professional engineer in Missouri and use 10 CSR 20-8.020, Design of Small Sewage Works, for specific design requirements not included as part of this fact sheet to ensure the surface land application of the wastewater can be considered exempt from permitting.

Two typical types of irrigation systems used for the surface land application of wastewater are a portable pump with movable sprinklers and a pump with a solid-set sprinkler system. Either system must be designed to handle lagoon effluent in such a manner that there is no discharge to waters of the state or other violations.  It is the facility owner’s responsibility to demonstrate to the Department of Natural Resources that all irrigation equipment is under their direct control and the land application site is part of the same contiguous operating location which is owned, operated or controlled by them or as tenants.

The wastewater should be land-applied when the wastewater level in the lagoon reaches the 5 foot water depth, until the level in the lagoon is lowered to the 2 foot water depth, as the soils allow. This process should be performed before winter, since wastewater cannot be land applied when the ground is frozen or snow covered. In addition, wastewater cannot be land-applied when the soil is saturated.

The Department of Natural Resources strongly recommends the following for the surface land application areas:

As described in 10 CSR 20-6.015 (2)(B), if the Department of Natural Resources determines that construction or operating practices of the surface land application sites are not adequate, permits can be required to ensure the facility is protective of the environment and public health.

Summary
If the no-discharge lagoon is followed by surface land application and satisfies the exemption, then it is exempt by rule unless the Department of Natural Resources determines its operation is not adequate. The burden of proof for the exemption is on the facility owner and it is their responsibility to demonstrate to the Department of Natural Resources that the system is and should be exempt.

As described in 10 CSR 20-6.015 (2)(B), nothing shall prevent the Department of Natural Resources from taking action to ensure that facilities do not discharge into surface or groundwater, including requiring permits for facilities that were previously exempt. The Department of Natural Resources may require permits to correct noncompliance, or when the Department of Natural Resources determines that construction or operating practices are not adequate, or for the protection of public health and the environment.

The no-discharge permit exemption does not excuse any facility or any person from complying with or from liability for violations of the Missouri Clean Water Law and regulations or any other 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.

As of Jan. 12, 2015, the construction of all new 3,000 gallon per day or less no-discharge lagoons where the accumulated wastewater will be pumped and hauled to a permitted facility, are required to obtain construction and subsequent operating permits from the Department of Natural Resources. All existing 3,000 gallons per day or less no-discharge lagoons shall be reviewed on a case-by-case basis to determine if permits are required.