Carson City officials said Douglas County wastewater prompted an Environmental Protection Agency allegation that the city was violating the Clean Water Act’s pretreatment program.
Carson City Director of Public Works Darren Schulz said there is an existing agreement with Douglas County “to remove a portion of their North County sewer that requires more pre-treatment requirements.”
EPA auditors found “incomplete documentation of Douglas County inspections.”
No fines were issued in a settlement between Carson City and the EPA.
“The Douglas County permit indicated that flow-weighted average concentration would be used, but no calculation was on file. Some raw analytical results exceed local limits for BOD, sulphides and phenolics. »
Carson City Wastewater Department Manager Andy Hummel said there was no pollution in the Carson River from city facilities.
“The samples that exceed BOD, phenolics and sulfides were taken by Douglas County personnel as part of their permit compliance,” Hummel said. “These tests are indicators of the strength of the wastewater and the amount of grease/oil/grease (or FOG) in the wastewater. These compounds are usually largely removed by grease interceptors installed in restaurants and other businesses that would produce them. If not removed, it creates more “work” for the treatment plant due to its resistance, and FOG can clog pipes and create hydrogen sulfide gas causing odors and corrosion at long term. The test point in the permit for sampling is the Douglas County lift station that pumps flows to our system; lift stations are notorious for collecting FOG because the pumps are at the bottom of the station and the FOG floats to the top, accumulating over time. Every time they had a high reading, the first step was to have them clean the station and retest, which fixes the problem. »
Hummel said Douglas County is responsible for controlling the preprocessing of individual businesses in that county.
“Individually, neither company would be considered a significant industrial user, but since Douglas County collectively sends us over 25,000 gallons of wastewater per day (one of the triggers for defining an SIU), Douglas County is considered an SIU,” he said. “That’s a big part of what the EPA didn’t like about our agreement and license with Douglas County. They wanted more enforcement “teeth” (which also drove updates to our enforcement response plan) and demanded that a new permit and agreement be issued.
Carson City takes sewage from the Clear Creek and Carson Valley plazas located near the Douglas County line. At some point, this wastewater should be treated at the North Valley Wastewater Treatment Plant.
“Western water bodies, such as the Carson River, are already under threat from climate change and drought,” EPA Pacific Southwest Regional Administrator Martha Guzman said in a statement. “Industrial wastewater pretreatment provides important protections for city infrastructure, residents and workers, and downstream waters.
Hummel said the errors found were all technical in nature.
“The pre-treatment program licenses and inspects the various industrial, manufacturing and commercial businesses in Carson City to prevent the release of chemicals into the sanitary sewer system that could impact treatment plant processes,” said he declared. “The findings of the audit related to code updates needed to match current EPA standards, authorization language needing updating, better tracking and authorizing needed software, and need for an updated application response plan. No findings or claims regarding pollution released into the Carson River have been made.
No fines were imposed by the federal agency. A corrective plan is in place which the city is following.
Hummel said the city was working diligently to comply with the agency’s request.
“As for next steps, we submitted revised code language to the EPA in May, which will be submitted to the oversight board for review once approved by the EPA,” he said. “An updated response plan was submitted to the EPA two weeks ago. Environmental Control staff are currently updating all permits to include the requested language. We have also acquired a new licensing software solution specifically designed for environmental monitoring permits and are currently implementing this system. The corrective action agreement specified certain dates for the agreed items; we are on schedule or ahead of schedule to complete all tasks.