On 17 September 2026, a Maryland state senator filed legislation aimed at tackling the persistent sewage odor that has hung over eastern Baltimore County for decades around the Back River Wastewater Treatment Plant, ordering a study and a prevention plan tied to the next General Assembly session WMAR 2 News Baltimore. The plant, run by Baltimore City, sits just south of the Back River between Dundalk and Essex, and Republican state Sen. Johnny Ray Salling, who represents the district, is the sponsor WMAR 2 News Baltimore.
Key takeaways
- Salling's bill will include a study and prevention plan and is to be formally introduced in the 2027 Maryland legislative session WMAR 2 News Baltimore.
- Baltimore City operates the Back River plant, which sits between Dundalk and Essex WMAR 2 News Baltimore.
- Resident Sam Weaver of the Maryland Waterways Foundation said he has smelled the odor for 70 years and that complaints have long gone unheard WMAR 2 News Baltimore.
- A 10 September WBAL-TV report said the latest Maryland Department of the Environment inspection identified excess sludge in lagoons, broken hydrogen sulfide sensors in odor scrubbers, and discharge limits being exceeded WBAL-TV.
- Baltimore City Department of Public Works told WBAL-TV it is developing a comprehensive odor control plan, with third-party engineer results due by year-end or early January WBAL-TV.
What happened
The odor issue is decades old, according to Salling, who said the fix is not a single problem but "many problems" WMAR 2 News Baltimore. "We need to make sure that we can control this. It is an issue. It is a problem, but we need to get good legislation," Salling said WMAR 2 News Baltimore. His legislation pairs a study with a prevention plan, with formal introduction set for the 2027 session WMAR 2 News Baltimore. Baltimore City declined an on-camera interview, saying the subject-matter expert was out of the office WMAR 2 News Baltimore.
Reporting on 10 September set out the operational drivers behind the smell. The Maryland Department of the Environment inspection cited excess sludge stored in lagoons, broken hydrogen sulfide sensors inside odor scrubbers, and pollutant discharge levels exceeding legal limits WBAL-TV. Baltimore City DPW said it is acting on those findings and that a third-party engineer's analysis is expected by the end of the year or early January WBAL-TV. Baltimore County Delegate Robert Long, R-District 6, said he is organizing a town hall and has reached out to the Philadelphia EPA for help WBAL-TV. "People can't open their windows. They can't eat. I mean it's affecting businesses. It's got to be fixed," Long said WBAL-TV.
Maryland waterways advocate Sam Weaver, who said the smell has been a constant for 70 years, told WMAR-2 the fatigue is real. "I think that's part of the problem is that, you know, we've all complained about it for so long, and we've had deaf ears," Weaver said WMAR 2 News Baltimore. Long added that he has been working the issue for "8 to 10 years" and is encouraging residents to appeal their property tax bills WBAL-TV.
Reported operational issues at a glance
| Issue identified | Source |
|---|---|
| Excess sludge stored in lagoons | WBAL-TV |
| Broken hydrogen sulfide sensors in odor scrubbers | WBAL-TV |
| Discharge levels exceeding legal limits (per February MDE inspection) | WBAL-TV |
| Third-party engineer analysis due by year-end or early January | WBAL-TV |
Specification read
The Back River plant is a large municipal works whose reported problems are upstream of disinfection: sludge storage, gas-phase H2S capture, and effluent compliance WBAL-TV. None of the supplied sources state a design flow in million litres per day or a population equivalent, so the headline hydraulic figure is not reportable from these texts; class size for a major US metro secondary plant of this type typically sits in the 250,000–1,000,000 m³/day range (general industry range, not from the sources). The treatment train the buyer should map this event against is the conventional municipal sequence: screening and grit removal → primary clarification → biological treatment (commonly activated sludge, with MBR or MBBR retrofits where footprint or effluent quality is constrained) → tertiary filtration and disinfection, with odor control applied at the headworks, primary clarifiers, and sludge-handling streams via chemical scrubbing, biotrickling, or activated-carbon polishing. The WBAL-TV inspection findings — lagoon sludge accumulation, failed H2S sensors in scrubbers, and exceedance of discharge limits — point squarely at the sludge-handling and gas-phase control stage, and at the biological/clarifier interface that sets effluent quality. The bill introduced by Salling pairs a study with a prevention plan to be filed in the 2027 session, which for procurement teams signals a likely forthcoming scope covering scrubber sensor replacement, lagoon sludge removal or digestion upgrade, and possibly tertiary or odor-control capital works WMAR 2 News Baltimore. If your plant looks like this — a metro Municipal secondary works in the 250,000–1,000,000 m³/day class (general industry range, not from the sources), with H2S-bearing sludge streams, lagoon storage, and tightening effluent limits — the procurement read is to pre-evaluate Air Dust Treatment and Integrated Sewage Treatment packages now, before the 2027 study translates into mandated equipment lists.
FAQ
What is actually in the senator's bill?
The legislation orders a study and a prevention plan and is slated for formal introduction in the 2027 Maryland General Assembly session WMAR 2 News Baltimore. No capital line item or budget figure was reported.
What did the latest state inspection find at Back River?
The Maryland Department of the Environment inspection cited excess sludge in lagoons, broken hydrogen sulfide sensors in odor scrubbers, and discharge levels exceeding legal limits, as noted in February WBAL-TV. Baltimore City DPW said results from a third-party engineer's analysis are expected by year-end or early January WBAL-TV.
What is the likely treatment stage this affects?
The reported failures sit at the sludge-handling and gas-phase control interface, with secondary biological and clarifier performance driving the discharge exceedance; expected remediation covers scrubber sensor replacement, sludge removal or digestion upgrade, and possible tertiary polishing (general industry mapping, not from the sources).
What should a buyer track between now and the 2027 session?
Track the third-party engineer report due by year-end or early January, the text of the 2027 bill, and any MDE corrective-action schedule that comes out of the study (general industry expectation, not from the sources). Capital-cost ranges for municipal odor-control retrofits at this scale typically run from low single-digit USD per population equivalent for chemical scrubbing to materially higher figures for full biotrickling or activated-carbon systems (general industry range, not from the sources).
