Get Full Government Meeting Transcripts, Videos, & Alerts Forever!
Get email alerts on the H2s Monitoring topic
No spam. Unsubscribe anytime.
County reports hydrogen sulfide levels below DEC standard near Monroe sewer corridor; mitigation ongoing
Summary
Weekly hydrogen sulfide monitoring around Monroe pump stations and manholes shows ambient readings well below the DEC standard of 0.01 parts per million; county staff said they continue manhole sealing, vent maintenance and coordination with municipal pump‑station treatments to reduce odors and corrosion.
At the Aug. 19 advisory committee meeting, county operations staff reported hydrogen sulfide (H2S) monitoring in the Monroe pump‑station corridor and said weekly ambient and fugitive‑gas readings remain well below the New York State Department of Environmental Conservation (DEC) standard of 0.01 parts per million (ppm) averaged over sampling periods.
The update is significant to residents because hydrogen sulfide is both an unpleasant‑odors source and — at higher sustained concentrations — a corrosive gas that can damage sewer infrastructure.
Robert Gray (referred to in the meeting as "Bob"), a county operations official, described the monitoring program and weekly reporting provided to the municipalities. "We monitor ... hydrogen sulfide is a gas that's formed by decomposition of organic matter," Gray said, noting meters were installed in manholes along the corridor and that the team also conducts fugitive‑gas ambient sampling. He cited sample averages from the most recent week of monitoring of about 0.0006 ppm and a higher sample of about 0.0011 ppm, both well below DEC's 0.01 ppm standard.
Gray said monitoring serves two purposes: tracking odorous emissions that generate community complaints and tracking corrosive conditions inside manholes that could affect concrete and pipes. The county provides weekly reports of the readings to the villages of Chester and South Blooming Grove and the Town and Village of Monroe, he said.
Field mitigation measures described in the meeting include resealing and, in some cases, closing manholes, changing vent‑filter cartridges, and targeted maintenance visits. Gray said Chester operates an oxygenation system that aerates sewage at its pump station to reduce H2S formation, while South Blooming Grove treats its wet well with sodium hypochlorite; the county said it maintains regular contact with municipal operators and checks key systems at least three times per week. Gray also described a recent short supply interruption in South Blooming Grove where chlorination was briefly reduced while product was reordered; staff said deliveries arrived within hours.
Committee members asked about increased monitoring sensitivity; Gray said the county has ordered a more sensitive ambient meter that will record continuous readings and produce a readout for inclusion in the weekly reports once it arrives.
No regulatory exceedances were reported to the committee. County staff said they will continue weekly monitoring, manhole sealing and coordination with municipal pump‑station treatment systems and will include the higher‑sensitivity meter results in future reports when the instrument is available.
