WHEN IS A SEPTIC SYSTEM 

REGULATED AS A CLASS V WELL? 

Underground Injection 

Control Program Audience:	 This fact sheet is for state, tribal, and local regulators; health 

department officials; environmental quality officers; and other persons 

who design, track, inspect, or issue permits for septic systems. 

Purpose:	 To help identify when a septic system would be regulated as a Class V 

well. 

WELLS OR INJECTION WELLS 

A well or injection well is a bored, 

drilled, or driven shaft, or dug hole, 

whose depth is greater than its largest 

surface dimension; an improved sinkhole; 

or a subsurface fluid distribution system 

used to discharge fluids underground 

(40 CFR 144.3). 

CLASS V WELLS 

Class V wells are typically shallow 

“wells,” such as shallow disposal 

systems and dry wells, used to place a 

variety of fluids directly below the land 

surface (40 CFR 144.80 (e)). 

SANITARY WASTE 

Sanitary waste is liquid or solid waste 

originating solely from humans and 

human activities, such as waste collected 

from toilets, showers, wash basins, sinks 

used for cleaning domestic areas, sinks 

used for food preparation, clothes 

washing operations, and sinks or 

washing machines where food and 

beverage-serving dishes, glasses, and 

utensils are cleaned (40 CFR 144.3). 

INDUSTRIAL OR 

COMMERCIAL WASTE 

For the purpose of this fact sheet, 

industrial or commercial waste can 

include, but is not limited to, any waste 

that results from manufacturing or other 

industrial and commercial processes. 

DEFINITIONS 

WHY IS EPA CONCERNED ABOUT SEPTIC 

SYSTEMS? 

Septic systems are commonly found in rural and suburban areas where populations also rely on ground water for drinking water. Many septic 

systems are 

located in close 

proximity to 

private drinking 

water wells or 

public water 

systems that 

use ground 

water sources. 

When septic 

systems are 

properly sited, 

designed, 

constructed, and operated, they pose a minimal threat to drinking water 

sources. Alternatively, poorly designed, maintained, and operated septic 

systems can contaminate ground water and surface water with nutrients, 

toxic chemicals, and pathogens. 

Septic systems are designed solely to treat sanitary waste. The disposal of 

industrial or commercial waste into a septic system can seriously inhibit 

wastewater treatment and cause the system to fail. More important, 

chemicals can pass through the system, enter the ground water, and pose 

a serious contamination threat. This was the case at a shopping center 

in Virginia. 
WHAT WENT WRONG? 

A contractor conducting routine sampling found high levels of two 

solvents, trichloroethylene (TCE) and perchloroethylene (PCE), in the septic 

system leach field of a shopping center in Virginia. 

water wells were also found to be contaminated. 

PCE have the potential to cause liver damage and cancer in humans. 

result, homes and businesses affected by the contamination were forced to 

abandon their drinking water wells and switch to bottled water until they 

could be connected to a public water system. 

was linked to businesses inside the shopping center that improperly 

disposed of their commercial wastewater into the septic 

businesses were, therefore, responsible for funding the costly cleanup, 

which could have been avoided if they had properly disposed of their 

commercial wastewater. 

Nearby private drinking 

If consumed, TCE and 

As a 

The source of contamination 

system. These 

WHEN IS A SEPTIC SYSTEM REGULATED AS A CLASS V WELL? 

EPA is directed by the Safe Drinking Water Act (SDWA) to establish minimum federal requirements for state* and 

tribal Underground Injection Control (UIC) Programs to protect underground sources of drinking water from 

contamination caused by underground injection activities. Protection includes the oversight of construction, 

operation, and closure of injection wells. A septic system** is required to meet UIC Program requirements and is 

considered a Class V well if either one of the following conditions is met: 

• 	The septic system, regardless of size, receives any amount of industrial or commercial wastewater (also known 

as industrial waste disposal wells or motor vehicle waste disposal wells); or 

• 	The septic system receives solely sanitary waste from multiple family residences or a non-residential 

establishment and has the capacity to serve 20 or more persons per day (also known as large-capacity 

septic systems). 

WHAT ARE THE MINIMUM FEDERAL REQUIREMENTS FOR CLASS V WELLS? 

Owners or operators of industrial waste disposal wells and large-capacity septic systems must meet state* and 

federal requirements. The minimum federal requirements for Class V wells are: 

1. Obey the non-endangerment performance standard prohibiting injection that allows the movement of fluids 

containing any contaminant into underground sources of drinking water, if the presence of that contaminant 

may cause a violation of any primary drinking water regulation or adversely affect public health; and 

2. Provide inventory information (including facility name and location, legal contact name and address, 

ownership information, nature and type of injection wells, and operating status of the injection wells) to the 

state or EPA regional UIC Program. 

* States may have additional or more stringent requirements. 

** Single family residential septic systems and non-residential septic systems that are used solely for sanitary waste and 

have the capacity to serve fewer than 20 persons a day are excluded from the UIC requirements (40 CFR 144.81(9)). 
WHAT ADDITIONAL REQUIREMENTS APPLY TO SEPTIC SYSTEMS THAT 

RECEIVE MOTOR VEHICLE WASTE? 

I

n 1999, EPA published the Class V rule, which requires owners and operators of motor vehicle waste disposal (MVWD) 

wells to meet the following additional requirements: 

• New MVWD wells are banned as of April 2000. 

Therefore, motor vehicle maintenance and repair 

facilities can no longer construct or install wastewater 

disposal devices that allow service wastewater to 

enter sinks and floor drains connected to septic 

systems. 

• Existing wells in regulated areas are banned and are 

required to be closed by January 2007. States and EPA 

regions may allow some facilities to continue 

operating their wells under a UIC permit or, in limited 

cases, to convert them to another type of well. 

Contact the appropriate EPA regional or state UIC 

Program to determine what areas are regulated in 

your state. 

MOTOR VEHICLE WASTE 

DISPOSAL WELLS 

Shallow waste disposal systems that receive or have 

received fluids from vehicle repair or maintenance 

activities, such as auto body or automotive repair, 

car dealerships, or other vehicular repair work, are 

required to meet additional protective requirements. 

WHERE MIGHT YOU FIND A SEPTIC SYSTEM OPERATING AS A CLASS V 

WELL? 

Facilities whose septic systems may receive industrial or commercial wastes include: 

• Electroplating Shops • Dry Cleaning Operations • Photo Processing Operations 

• Mortuaries • Taxidermy Shops • Food Processing Operations 

• Beauty Salons • Print Shops • Car Washes 

WHAT CAN YOU, AS A LOCAL OFFICIAL, DO IF YOU FIND A SEPTIC 

SYSTEM OPERATING AS A CLASS V WELL? 

If you have, or think you may have, identified a septic system that receives industrial or commercial waste, you should 

contact the appropriate EPA regional or state UIC Program. UIC officials can offer advice and assistance with your 

concerns. A list of UIC Program contacts is available at www.epa.gov/safewater/uic/states.html. 
HERE


AGE
 POST

WHEN IS A SEPTIC SYSTEM REGULATED AS A CLASS V INJECTION WELL? 

This fact sheet is for state, tribal, and local regulators; health department 

officials; environmental quality officers; and other persons who design, 

track, inspect, or issue permits for septic systems. The purpose of this fact 

sheet is to help identify when a septic system would be regulated as a 

Class V well. 

FOR MORE INFORMATION... 

UIC and Class V Wells Office of Ground Water and 

Drinking Water (4606M) 

What is the UIC Program? Web site: 

www.epa.gov/safewater/uic/whatis.html 

Shallow Injection Wells (Class V) Web site: EPA 816-F-03-002 

www.epa.gov/safewater/uic/classv.html www.epa.gov/safewater 

General Information: 

SDWA Hotline: 1-800-426-4791 June 2003 

UIC Program Contact Web site: 

www.epa.gov/safewater/uic/states.html 

EPA’s Onsite/Decentralized Wastewater Treatment 

Systems Web site: 

www.epa.gov/owm/mtb/decent/ 

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