Cooling Water Intake Structure

​Columbia Generating Station gets its cooling water from the Columbia River “through two 42-inch diameter inlets perforated with 3/8 inch diameter holes, each approximately 20 feet long and placed parallel to river flow approximately 350 feet offshore at low water. Water flows by gravity to the River Pumphouse. The intake structures for CGS were designed and constructed in the late 1970s.” (CGS-NPDES Fact Sheet p.20).



As the fact sheet also points out, the intakes were designed “to minimize the impact of make-up water from the Columbia River, with particular emphasis on salmonid fry.” And that’s what it has been doing for 30 years.

How do we know this? Two studies that were conducted, both pre- and post-operational.

In the 1985 study the monitoring program looked at both impingement and entrainment between April and September. No juvenile salmonids were found to be affected. This monitoring program was undertaken with study-plan review by the National Marine Fisheries Service.

 

The Role of the NMFS

The NMFS opinion on our intake structure has been found to be without merit twice (the first time being Columbia’s license renewal where the Nuclear Regulatory Commission found their argument uncompelling).

In part this is because the NMFS design criteria for intake structures pertains to models not utilized by Columbia Generating Station. As Dr. Charles Coutant wrote in his discussion paper prepared for a meeting with the agency in 2013: “NMFS does not have design criteria specifically for cylindrical screens oriented parallel with the current in flowing water...”

Still, EFSEC wanted to address the NMFS concerns. So in the new permit a new study will be undertaken to update the entrainment data from the 1985 study that found zero impact on fish. The science will inform us.

The EPA and Cooling Water Intakes

The Environmental Protection Agency issued its final rule (316b) regarding cooling water intakes for existing power plants in May, 2014. The rule is designed to better protect fish and aquatic life in all bodies of water.

From the EPA news release:
“Existing facilities that withdraw at least 25 percent of their water from an adjacent waterbody exclusively for cooling purposes and have a design intake flow of greater than 2 million gallons per day are required to reduce fish impingement. To ensure flexibility, the owner or operator of the facility will be able to choose one of seven options for meeting best technology available requirements for reducing impingement.”

Columbia Generating Station falls into this category.

The EPA rules goes on to explain “(a)s a result, existing facilities may comply with the impingement mortality requirements by implementing any one of the following seven options: operate a closed-cycle recirculating system (e.g., cooling towers)” (emphasis added).

 

 Who is EFSEC?

The State of Washington Energy Facility Site Evaluation Council (EFSEC or Council) provides a "one-stop" siting process for major energy facilities in the State of Washington. EFSEC coordinates all evaluation and licensing steps for siting certain energy facilities in Washington. EFSEC specifies the conditions of construction and operation. If approved, a Site Certification Agreement is issued in lieu of any other individual state or local agency permits. EFSEC also manages an environmental and safety oversight program of facility and site operations. Learn more here.