Division Links

Large-Capacity Cesspools (EPA Well Code—5E):
Utah Underground Injection Control (UIC) Program

New large-capacity cesspools are BANNED nationwide as of April 5, 2000. Existing large-capacity cesspools must be closed by April 5, 2005.

What is a Large-Capacity Cesspool?

Cesspools are shallow onsite wastewater disposal systems used to dispose of untreated sanitary waste. Although the construction of a cesspool may vary, they typically consist of concrete cylinder with an open bottom or perforated sides or a pit lined with bricks or cinder blocks. In Utah, cesspools are considered to be Large-Capacity Cesspools (LCCs), regulated by the Utah UIC Program, if the cesspool is used for the onsite disposal of solely untreated sanitary waste by:

  • a multiple dwelling residential facility (e.g., a townhouse complex or apartment building), or
  • a non-residential facility where the cesspool has a design capacity of greater than 5,000 gallons per day.

Note: The 5,000 gallons per day flow rate limit does not apply to multiple dwelling residential facilities. Any cesspool used at one of these facilities must be closed.

Example of a Large Capacity Cesspool

Large Capacity Cesspool old-timey illustration

The Utah UIC Program does not regulate cesspools used by single family homes or non-residential cesspools with a design capacity of less than or equal to 5,000 gallons per day to dispose of solely sanitary waste. Therefore, these smaller systems are not affected by the new requirements. Please contact your Utah local health department for more information.

Where are Large-Capacity Cesspools in Operation?

In general, the following facilities may use large-capacity cesspools :

  • multi-family residential units
  • churches, schools, and public meeting facilities
  • office buildings
  • industrial and commercial buildings
  • shopping malls
  • hotels and restaurants
  • highway rest stops
  • state parks and camp
  • grounds
  • train and bus stations

Why are Large-Capacity Cesspools Banned?

Untreated sanitary waste discharged into a cesspool can enter shallow groundwater and contaminate drinking water resources because: they are designed to isolate but not to treat sanitary waste, the wastewaters from them frequently exceed drinking water health standards for nitrates, total suspended solids, and coliform bacteria, the wastewater may contain other constituents of concern such as phosphates, chlorides, grease, viruses, and chemicals used to clean cesspools (e.g., trichloroethane and methylene chloride), and areas that rely on cesspools are more likely to rely on groundwater for their drinking water supplies.

How Do I Know If I Have a Large-Capacity Cesspool?

Answer the following questions to determine if you may have a large-capacity cesspool.

Questions If Your Answer is Yes If Your Answer is No
Residential Properties
1. Do you own or operate a multiple-family dwelling (duplex, townhouse complex, apartment building, assisted living facility, nursing home, or cluster development)? Go to Question 3. Go to Question 2.
Non-Residential Properties
2. Does your facility generate more than 5,000 gallons per day of sanitary waste from toilets, showers, sinks and wash basins, food preparation sinks and basins, and clothes washing and dish washing machines? Go to Question 3. You are not affected by the new rule.
Stop here.
3. Is your sanitary waste discharged to a municipal sewer? You are not affected by the new rule.
Stop here.
Go to Question 4.
4. Is your sanitary waste discharged to a holding tank, and is the waste in the holding tank disposed of off-site? You are not affected by the new rule.
Stop here.
Go to Question 5.
5. Is your sanitary waste discharged to a septic system (that is, a septic tank with a leaching field) or package plant? *(see note below) You are not affected by the new rule.
Stop here.
You may be disposing your sanitary wastes into a large-capacity cesspool.

*Note: If you are not sure where your wastewater goes, use dye or smoke tests to help locate the discharge points for your bathrooms and kitchens. Your local health department, plumber, or licensed septic tank pumper may be able to help you determine where your sanitary waste goes.

Source: EPA’s Class V Wells.

What Are The New Class V Rule Requirements For Large-Capacity Cesspools?

The following discussion references the Utah Administrative Rules for the UIC Program and various sections of 40 CFR.

New large-capacity cesspools are banned nationwide as of April 5, 2000. Large-capacity cesspools may no longer be constructed. (New large-capacity cesspools are those for which construction was started on or after April 5, 2000 (R317-7-6.5(B))(See also 40 CFR § 144.88(a)(2)).

Existing large-capacity cesspools must be closed by April 5, 2005 (R317-7-6.5(A)) (See also 40 CFR § 144.88(a)(1)(i)).

What are the Requirements For Closing Large-Capacity Cesspools

In Utah, you must close your large-capacity cesspool in a “… manner that prevents the movement of fluid containing any contaminant into an underground sources of drinking water, if the presence of that contaminant may cause a violation of any primary drinking water regulation under 40CFR Part 141 or Utah Public Drinking Water Rules R309-100, or may otherwise adversely affect the health of persons.” (R317-7-6.6(A)) (See also 40 CFR § 144.12).”

In closing your large-capacity cesspool, the owner or operator must:

  • Notify the Utah UIC Program of the intent to close the large-capacity cesspool at least 30 days prior to closure (R317-7-6.6(C)) (See also 40 CFR § 144.88(a)(1)(ii)). Contact the Utah UIC Program and ask if they want you to fill out a pre-closure notification form, a Utah UIC inventory information form or write a letter. Send this notification at least 30 days before physically closing the large-capacity cesspool. Closure may not commence until a letter from the Utah UIC Program, approving the closure plan, is received.
  • Permanently plug or otherwise close the large-capacity cesspool in a way that ensures underground sources of drinking water are protected and is approved by the Utah UIC Program (40 CFR §§ 144.89(a) and 146.10(c)(1)).
  • Dispose of or otherwise manage any soil, gravel, sludge, liquids, or other materials removed from or adjacent to the large-capacity cesspool according to all applicable Federal, State, and local regulations and requirements (R317-7-6.6(B)) (See also 40 CFR §§ 144.89(a) and 146.10(c)(2)).

What are the Sanitary Waste Disposal Options After Closing Large-Capacity Cesspools?

There are numerous alternatives to the use of large-capacity cesspools. The following alternatives are some you might consider:

  • Sanitary Sewer Hookup: Contact the local sewer authority about the possibility of connecting your multi-family residential facility or non-residential facility to the sewer system. Often, system hookup may be available even though it was not an option when your home or building was first constructed. Because sanitary wastes are treated and disposed of properly, sewer hookup is the best option, both for you, and the environment. However, it can be expensive.
  • Holding Tanks: Store the sanitary waste in a holding tank. The tank is then periodically pumped out for proper disposal. You may minimize the amount of wastewater that has to be stored by implementing water conservation practices (e.g., using low flow shower heads and low flow toilets). In Utah, sewage holding tanks are subject to Utah Administrative Rules for Onsite Wastewater Systems. Please contact your Utah local health department for more information.
  • Large Underground Domestic Wastewater Disposal System: Large underground domestic wastewater disposal systems with a design flow rate of greater than 5,000 gallon per day of treated sanitary waste are subject to the Utah Administrative Rules for Large Underground Wastewater Disposal Systems. Please contact Ed Macauley (emacauley@utah.gov) of the Utah Division of Water Quality to discuss the construction requirements for these systems. These systems with a design flow rate of greater than 5,000 gallons per day are also regulated by the Utah UIC Program. Owner / operators of these systems are required to submit UIC Inventory Information prior to the construction of the system.
  • Package Plants: Small wastewater treatment systems, known as package plants, are designed to treat limited sewage flow from suburban residential developments, hotels, schools, and other relatively isolated wastewater sources. These package plants use prefabricated steel tanks and hold the wastewater for a longer duration as part of their wastewater treatment process. You are required to obtain permission or authorization to construct and use package plants. In addition, depending on local environmental conditions, you may be required to use certain alternatives to remove specific contaminants prior to discharging the wastewater into the environment.

This Web page represents a modification of an EPA Website to reflect Utah Administrative Rules and Requirements.

Contact Porter Henze (pkhenze@utah.gov) with questions or comments.

Last Updated:


Back to top