The Orange Water and Sewer Authority, which delivers water services to the Chapel Hill and Carrboro communities, released its annual wastewater report card for 2022 on Feb. 20.
The report card includes information about wastewater overflows and chemicals released during the year.
Mary Darr, the general manager of operations for OWASA treatment plants and laboratories, said the authority was happy with its overall results this year. All of the regulatory Environmental Protection Agency requirements were met.
In 2022, OWASA measured more than 100,000 pounds of nitrogen in local wastewater and almost 2,000 pounds of phosphorus, which are 18.7 percent and 80.6 percent below the regulatory limits, respectively.
In biosolids, which OWASA separates from liquids at its treatment plant, none of the recorded substances — including lead, mercury and arsenic, among others — were above the regulatory limits.
“This is the Mason Farm Wastewater Treatment Plant’s 13th consecutive year with 100 percent compliance and no violations at the WWTP," Wil Lawson, OWASA's wastewater treatment plant and biosolids recycling manager, said in an email.
All of the community’s wastewater is carried by about 350 miles of underground sewer pipes that are maintained by OWASA. When the wastewater gets to the plant, the authority begins the process of treating the water so it can be reused for non-drinking purposes or released into Morgan Creek.
OWASA replaced 1,141 feet of sewer lines and installed more than 2,800 feet of new sewer lines in 2022.
The organization is required to test five days per week, excluding holidays. It has an in-house lab that is certified to run several analyses and it utilizes a contract lab for other tests.