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UIC Frequently Asked Questions

This webpage provides answers to common questions about regulation of Underground Injection Control (UIC) devices in Oregon. If you do not see your question, or if the answers are unclear, please contact the UIC hydrogeologist at 503-229-6371 for further assistance.

UIC Definitions and Basic Questions 

What is UIC?
​In general, a UIC, or Underground Injection Control, is a drywell, assemblage of perforated pipes, or drain tiles that are used to place fluids underground. UIC regulations do not apply to swales, french drains, or footing drains.
Why does DEQ regulate UICs?
​Oregon regulates UICs to protect groundwater resources. In Oregon, 70 percent of communities depend on groundwater as their source of drinking and irrigation water. Fluid injected into the ground that is contaminated from sources such as industrial businesses, auto repair shops, chemical spills and animal waste may reach groundwater through improperly or illegally used UICs, causing groundwater contamination. Once groundwater contaminated, it is costly, difficult, and sometimes impossible to clean up.
What do I need to do if I have a UIC, and want to continue using the UIC?
​Active UICs must be authorized by DEQ, either by rule or by permit. Authorization by rule is the simplest and most cost effective way to have a UIC authorized, but UICs can only be authorized by rule if the UICs meet certain conditions.
UICs that drain roof-only runoff can be authorized by rule. UICs that drain stormwater from parking lots, streets and/or driveways can be authorized by rule if all of the following are true:

  • The UIC is located more than 500 feet from the nearest water supply well,
  • The UIC is located outside of the two-year time-of-travel for a municipal water well,
  • The UIC does not intersect the seasonal high groundwater table,
  • The UIC does not impact contaminated soil or groundwater,
  • Structural and non-structural best management practices are used for source control and treatment, and
  • Stormwater that drains to the UIC is not exposed to hazardous materials

If a UIC does not meet one or more of the conditions above, the UIC must be authorized by permit or closed.
To apply for authorization of a UIC, submit an application to DEQ.
What do I need to do if I have a UIC, and want to stop using the UIC?
​UICs that are not being used must be closed in a manner that prevents vertical migration, or movement, of fluids in soil. To apply for closure of a UIC, submit a Pre-Closure Notification to DEQ. DEQ’s fact sheet “Closure of an Injection System” discusses the procedure for closing a UIC.
How do I submit my application?

​Mail the application and fee to DEQ’s business office, at

700 NE Multnomah Street, Suite 600,
Portland, OR 97232,
and email an electronic copy to UIC@DEQ.state.or.us.


UIC Fees 

What are the fees for authorization of remediation UICs?
​If your project is in DEQ’s Independent or Voluntary Cleanup Program, DEQ does not charge fees for UICs. If the project is not in the Voluntary Cleanup Program, the fee is $134 per group of UICs used for injection.
What are the fees for authorization of stormwater UICs?
​Fees for stormwater UICs depend on whether the UIC is authorized by rule or by permit. The fees for authorization by rule are:
  • $107 per UIC for UICs that discharge roof-only runoff (commercial, industrial, and triplex or larger residential)
  • $134 per UIC for UICs in drainage basins with less than 1,000 vehicle trips per day.
  • $321 per UIC for UICs in drainage basins with more than 1,000 vehicle trips per day. In addition, these UICs are subject to an annual fee of $107 per UIC.

Fees for authorization by permit are:

  • For an individual permit, $15,504 application fee and $3,282 annual fee
  • For a general permit, $616 application fee and $633 annual fee, plus rule authorization fees
What are the fees for closure of stormwater UICs?
​The fee for closure of a stormwater UIC is $107 per UIC.


UIC Closure 

Does a UIC that only receives stormwater from a roof require sampling before it is closed or decommissioned?
​No, UICs that discharge roof-only runoff do not require sampling before closure.
If I want to close multiple stormwater UICs at a site, do I have to sample all of them?
​No. Samples collected from a representative number of the UICs are sufficient.
What pollutants should I analyze before closing or decommissioning a stormwater UIC?
DEQ’s fact sheet “Closure of an Injection System” discusses sampling requirements as a part of UIC closure.
If my site has a UIC that was closed and never authorized, do I still need to apply for authorization of the UIC?
​If the UIC was completely removed or filled and capped with a material that prevents stormwater or other fluids from moving through the UIC, the UIC does not need to be authorized by DEQ. A cap material can include the asphalt pavement or concrete such as a road or parking lot. The intent is to stop stormwater or other fluids from entering the closed UIC and reaching groundwater.

If the UIC still exists and was not capped and filled with material that prevents movement of stormwater through the UIC, it can function as an active UIC. You must either formally close it or bring it into compliance as an active UIC by applying for authorization by rule or permit.
Download forms for UIC authorization and pre-closure notification.


UIC Authorization 

Do UICs have to be authorized by DEQ before installation?
​Yes, UICs must be authorized by DEQ before installation.
Do UICs that drain roof-only runoff at single family residential properties need to be authorized by DEQ?
​No, UICs that drain roof-only runoff from single family residential properties do not need to be authorized by DEQ. UICs that drain roof-only runoff runoff from duplex or larger residential properties need to be authorized by DEQ.
Do I have to register my driveway drain UIC?
​Yes. DEQ requires residential UICs receiving driveway runoff to be registered. The fee is $125 per UIC.
How do I know if a UIC on a property has been authorized by DEQ?
​Search DEQ’s UIC database. A UIC has been approved if the “Facility Status” is “Registered & RA,” “UIC WPCF,” or “Registered With Permit.”

If the UIC is not listed in the database, you will need to obtain authorization for the UIC. If the UIC cannot be authorized either through authorization by rule or acquiring a water pollution control facilities permit, the UIC must be formally closed.
How do I get a copy of a UIC approval letter, permit or other documents about a UIC?
​Complete a Public Records Request Form and submit it to DEQ.

Does DEQ require sediment testing for authorization of UICs?
Unless known or suspected contaminants have entered the UICs, DEQ does not require sediment testing.
When stormwater sampling is required at a site with multiple UICs, is a sample required for each UIC?
​No. DEQ can accept stormwater samples from a representative subset of UICs rather than a sample from each UIC. In a parking lot, sampling should focus on the area(s) with the most vehicle traffic such as near lot entrances and exits, near building front doors, and near loading docks.
Are UICs allowed in loading dock areas?
​The answer depends on the site use. If hazardous materials, toxic substances, or petroleum products are being loaded or unloaded, then a UIC is not allowed in the loading dock area. However, if the loading dock area is not used for loading and unloading of these materials, a UIC is allowed.
Do UICs within a residential development have to be authorized by DEQ?
​Yes. Regardless of land use, all UICs must be authorized by DEQ.
Can UICs be within the two year time of travel to a well?
​No, unless the owner seeks approval through an individual or general WPCF permit, or if the UIC is for disposal of roof runoff only. Approval through an individual or general WPCF permit requires that the UIC owner demonstrate that the UIC will not contaminate the water well.
Can UICs be within 500 feet of a water well?
​No, unless the owner seeks approval through an individual or general WPCF permit, or if the UIC is only for roof runoff disposal. Approval through an individual or general WPCF permit requires that the UIC owner demonstrate that the UIC will not contaminate the water well.
Do UICs need to have site specific infiltration tests?
​DEQ does not require site specific infiltration tests. However, local jurisdictions may require infiltration tests.
Do UIC owners need to look for alternative discharge methods other than UICs?
​DEQ does not require UIC owners to look for alternative discharge methods. However, local jurisdictions may require alternative discharge methods in some areas (for example, wellhead protection areas).
What are the pretreatment requirements for UICs?
​UICs are required to have pretreatment. Acceptable pretreatment types are provided in DEQ’s Industrial Stormwater Best Management Practices Manual.
What is the vertical separation requirement between the bottom of a UIC and the seasonal high water table? Is the vertical separation requirement still 10 feet?
​Drywells cannot intersect the groundwater table. DEQ recommends that drywells have at least five feet of vertical separation from the seasonal high groundwater table.
Does DEQ have to review and approve the design of UICs?
​No, DEQ does not review and approve the design of UICs.
At a commercial property, am I required to sample stormwater from UICs that receive stormwater runoff from roof downspouts?
​If one or more of the UICs are for roof runoff only, then those do not have to be sampled.
What are the minimum elements a site map should show?
​The site map must show the UICs labeled by name, property lines, adjoining streets, buildings, a north arrow, and an aerial photo.
Does DEQ review stormwater management plans for sites that are authorized by rule?
Yes. The UIC owner is required to prepare and implement a management plan, and submit it to DEQ in accordance with OAR 340-044-0018(3).
Does DEQ require that a UIC be accessible for maintenance?
​DEQ does not have an access requirement, but it is good practice to keep drywells reasonably accessible as they need to be serviced on a regular basis to maintain their functionality.


Site Changes

How do I inform DEQ of changes in the name or ownership of a site with a UIC?
​Complete the Transfer of Ownership or Operator form provided on DEQ’s UIC Program’s Registration Forms webpage and mail it to DEQ.
What do I need to provide DEQ if physical changes are planned for a site with an approved UIC?
​You must notify DEQ in writing if site alterations will result in reduced quality or increased quantity of water a UIC receives.