Underground Injection Controls

Underground Injection Control (UIC) facilities are rule authorized by the Oregon Department of Environmental Quality and may include any stormwater facility that infiltrates directly into the soil subsurface. This family of facilities definitely includes drywells and soakage trenches where volumes of runoff are infiltrated or "injected" into the subsurface via perforated manholes or pipes and could accidentally be incorporated into LID designs. There are several things about a detail of other infiltration facility types such as rain gardens, stormwater planters, and vegetated filter strips that could require review and/or rule authorization by the Oregon DEQ. See the table below.

Rule authorization or review by DEQ may be required: To avoid rule authorization by DEQ:

The facility serves as pretreatment for another UIC such as a drywell or soakage trench (see figure below). Cannot be avoided. This facility will be considered a part of the UIC that must be rule authorized.
The approved disposal point injects stormwater underground in any kind of facility. Make sure the approved disposal point is to either a public storm pipe or directly to surface waters.
The constructed facility is deeper than it is wide.
Make sure the dimensions of your facility are wider than they are deep. This includes the dimensions of any newly constructed parts of the facility such as the engineered planting soil.

 

 

 

A fully perforate pipe that receives runoff from anywhere has been buried.

 

Use a pipe not perforated on the bottom.

 

 

See UIC Regulations in individual fact sheets for other conditions that may cause review. See UIC Regulations in individual fact sheets for other design guidance on avoiding inadvertantly creating UICs during design.

 

 

A rain garden, even if it doesn't infiltrate, might be considered a UIC if it serves as pretreatment for a drywell, soakage trench or other regulated UIC.

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