Oregon

Underground Injection Control (UIC)

Agency Oregon Department of Environmental Quality

Oregon Underground Injection Control (UIC)

The Oregon Department of Environmental Quality (DEQ) operates Oregon's Underground Injection Control (UIC) Program through authorization from the Environmental Protection Agency. An underground injection system places fluids below the ground. DEQ says the most common UIC systems in Oregon are stormwater drywells, which are usually found on large parking lot surfaces or streets.

In a Phase I ESA

ASTM E1527-21 does not name injection system records among its standard record sources. They bear on a Phase I because an injection system places fluids below the ground: DEQ says the program's goal is to protect freshwater aquifers from contamination due to underground injection systems. Six details shape how to read one.

Every system is supposed to be registered. DEQ says all owners and operators of an injection system must register their systems and gain written DEQ approval to operate in one of three ways: by qualifying as rule authorized, by applying for a state permit, or by closing the injection system. For a drywell on a property, ask the owner for the registration and DEQ's written approval.
Stormwater is the main fluid, not the only one. DEQ says the fluids are mainly stormwater, but also water for aquifer storage and recovery, low temperature geothermal return water, treated drinking water and other fluids.
The land use decides the concern. DEQ says runoff from residential areas is the least likely to pollute groundwater, compared with runoff from industrial, commercial or transportation activities. It associates toxic organics most often with industrial and commercial sites that use, sell or produce gasoline, wood preservatives, oil, solvents, paints and pesticides, and says vehicle service areas have the greatest frequency and quantities of organics.
The setting decides the rest. DEQ says the risk depends on the quality and volume of the injected fluid, pretreatment before discharge, the depth of injection, the depth to the seasonal high water table, and the soil and geology. It says fractured rock and coarse-grained sediments let contaminants travel greater distances more rapidly.
The owner carries the burden of proof. DEQ says that under the federal rules it is the owner or operator, not DEQ, who must prove that an injection activity does not have the potential to violate the primary drinking water standards or adversely affect groundwater quality, human health or the environment. DEQ can require pretreatment, sampling and monitoring, a permit, or closure.
Some things that look like injection are not UICs. DEQ's exclusions include single family residential septic and cesspool systems receiving only domestic waste with drainfields, single family residential roof drains, non-residential septic systems handling only human sanitary waste and designed to serve fewer than 20 people per day or less than 2,500 gallons per day, and infiltration systems that discharge to surface water. DEQ notes that perforated piping under a detention pond would count as an injection system.

DEQ says the federal program was enacted in 1974 under the Safe Drinking Water Act and is administered under 40 CFR parts 144 to 146, that EPA gave DEQ authority to regulate UIC systems in 1984 and re-authorized the program in 1991, and that DEQ regulates the program under Oregon Administrative Rules Chapter 340, Division 44. It cites OAR 340-040 for the groundwater requirements.

Where to look a site up

The pages read name no public list or map of registered injection systems.
DEQ lists the program in Your DEQ Online as of October 1, 2021. The Your DEQ Online Public Records Portal has a Permits/Licenses/Certificates module of published records. The pages read do not say whether rule authorizations appear in it.
The UIC program is at UIC@deq.oregon.gov.

Getting the file

Ask for the registration, the rule authorization or permit, and any closure record. The pages read give no records route of their own for the program. DEQ's general route is described on the Your DEQ Online and public records requests page.

Sources

Oregon Department of Environmental Quality pages, read October 7, 2026, no modified date shown: