wastewater-biosolids-report-FY11

From July 2010 through June 2011, OWASA treated and recycled 2.7 billion gallons of wastewater and 1,279 tons of “biosolids” in accord with Federal and State standards.

OWASA surpassed the treated water quality standards for the utility’s Mason Farm Wastewater Treatment Plant including limits on bacteria, phosphorus, nitrogen and solids.

Most of OWASA’s treated wastewater is recycled to Morgan Creek, a tributary of Jordan Lake. Jordan Lake is a water source for several communities in the Triangle.

The University used about 170 million gallons of OWASA’s highly treated wastewater in a “reclaimed water” system that meets non-drinking water needs such as chilled water for cooling systems, irrigation and toilet flushing at certain facilities.

Biosolids are the solids that are separated from wastewater, treated in a biological break-down process and disinfected by heating them to 140 degrees. Biosolids are recycled on farmland to help grow crops for non-human consumption, or used in a composting process to make a soil additive for landscaping. OWASA’s biosolids surpass the U.S. Environmental Protection Agency’s standards for “Exceptional Quality” as shown below.

Substance

Federal Standard for

Exceptional Quality Biosolids

OWASA’s average

(July, 2010– June, 2011)

Fecal coliform bacteria

Maximum of 1,000 per gram

54 per gram

Mercury

Maximum of 17 parts per million (ppm)

1.27 ppm

Cadmium

Maximum of 39 ppm

2.15 ppm

Arsenic

Maximum of 41 ppm

1.51 ppm

Lead

Maximum of 300 ppm

8.58 ppm

Copper

Maximum of 1,500 ppm

283.58 ppm

Zinc

Maximum of 2,800 ppm

769.17 ppm

There were seven wastewater overflows from OWASA’s public sanitary sewer system in 2010-11, with a total estimated volume of 4,475 gallons or a fraction of one percent of the 2.7 billion gallons of wastewater treated.

OWASA’s annual report on wastewater and biosolids is being mailed to OWASA customers in August and is available on OWASA’s website via the following link:  Annual Report.

For more information:

  • Damon Forney, Wastewater Treatment and Biosolids Recycling Manager, 537-4352 or dforney@owasa.org
  • Thurman Green, Collection and Distribution Systems Manager, 537-4224 or tgreen@owasa.org
  • John Greene, General Manager of Operations, Water Supply and Treatment Manager, 537-4218 or jgreene@owasa.org