North Anna Waste Heat Treatment Facility

North Anna Waste Heat Treatment FacilityCooling Lagoons

North Anna Power Station uses water from Lake Anna to condense steam back to water inside the station. The water is returned to the lake slightly warmer than when it was taken. The discharged water cools in a series of private cooling lagoons, known as the Waste Heat Treatment Facility (WHTF).

When North Anna is in full operation, approximately 2,000,000 gallons of water pass through the station per minute.


Lake Anna was developed to provide cooling water for North Anna and is 17 miles long, 1 1/2 miles wide, and offers 200 miles of shoreline. Download a brochure on Lake Anna.

Lake Anna Conditions

Lake Anna's water level and temperature readings are updated once each weekday. The temperature is measured in water being drawn directly from the main lake into the station's intake. The lake level is based on feet above sea level as measured at the main dam.

Date Temperature (deg. F) Lake Level (ft.)
2/17/2018 46 250.1

WHTF Water Temperatures

Discharge Water

By design, the temperature of the discharge water is typically 14 degrees warmer than the intake water (displayed above). Intake temperatures can fluctuate with seasons or weather conditions. The data below is posted daily, M-F, as a public service. More frequent updates are forthcoming.

Temp. (deg. F)
11:30 a.m.

Lagoons 2 and 3

As the discharge water flows to lagoons 2 and 3, it gradually cools, and is eventually returned to the main lake. The period of primary recreational use in the lagoons (May 1 - October 31) is typically the period with the highest water temperatures and greatest recreational use. Individuals choosing to use the lagoons for recreational purposes should consider these temperatures in relation to health risk information contained on the Virginia Department of Health's website.