The Soapstone sewer rehabilitation project has an air quality monitoring plan and permit that will allow DC Water’s contractor to proceed with the pipe relining phase of the project, which is set to begin later this month.
“This is the agreed upon 14 days advance notice for CIPP work that will be done inside the park,” wrote Emmanuel Briggs, DC Water’s community affairs director, in an emailed December 8th notice. CIPP is cured-in-place pipe, and the process involves the onsite manufacture of a new lining for the 115-year-old sewer lines.
The work will begin with the sewer line running along the center of the park, and away from Soapstone-adjacent homes and businesses. Work on another line, parallel to Audubon Terrace, is to begin this spring. DC Water said the owners of the eleven properties affected will receive separate 14- and 7-day notices.
The air quality permit and monitoring plan were approved by the Department of Energy and the Environment (DOEE) on December 22nd. DC Water’s contractor will be lining the old metal sewer lines with a liquid resin, then pumping hot water through to harden the liner, hence “cured-in-place pipe.” The boiler truck that will be heating the water runs on propane gas, and gives off fumes. By regulation, this requires a DOEE air quality permit.
The air quality monitoring plan is for the CIPP work. Studies have shown that fumes laden with toxic chemicals can be released by the process, impacting the health of workers onsite and of occupants of neighboring homes, schools and businesses, should the emissions travel through sewer lines into those buildings.
Community members including now-former ANC 3F Commissioner Dipa Mehta, and newly sworn-in Commissioner Mitch Baer, have pushed hard for such monitoring and permitting. At ANC 3F’s December 13th meeting, they also pressed DC Water to clear up confusion about how many residences are connected directly to the sewer lines undergoing CIPP work. They wondered why the agency listed only eleven homes on Audubon Terrace, and not on residences on Lenore Lane and in the multi-family Park Van Ness, Park Connecticut, Van Ness East and Van Ness North.
The answer, after some back and forth, is that the other houses and buildings do not have direct connections to the sewer. Between the larger buildings and “the lines being lined there’s a manhole in between,” said DC Water engineer Will Elledge. “It’s an air brake, basically. It’s a disconnect between any air that would connect the sewer to the building.”
The eleven homes on Audubon Terrace connect to the sewer line through laterals. “Every other resident in the entire area has a manhole that’s breaking that gap,” Elledge said.
The difference is illustrated in the air quality monitoring plan with graphics that were not presented at any previous meeting.
The monitoring plan also lists the materials used in the resin liner, the chemicals emitted when the resin is heated, and the “action levels” for emissions and odors.
The plan presents odor intensity on a scale of zero to five, with zero for smells that are not detectable, and five for smells that are overpowering and intolerable.
Residents will have to rely on their noses. But the monitoring plan does not include information on how they and building managers can report odors.
In an email to Forest Hills Connection, Stephen Ours, DOEE’s air quality permitting branch chief, said odors reported by residents would be investigated, but he acknowledged the lack of a communication plan. He leaves this for DC Water to provide, and otherwise recommends contacting 311 by phone or online at 311.dc.gov, using the request type “DOEE – General Air Quality Concerns (Dust, Visible Emissions, Odor, Asbestos).” Residents can also email firstname.lastname@example.org.
According to the plan, most outdoor air quality checks will occur downwind of manholes. If emissions or odors above the specified levels are detected, the air monitoring contractor is to alert the construction manager, and they would work with the CIPP contractor on the response. DC Water is also to notify DOEE.
The report mentions only one condition for stopping the work: when total volatile organic compounds (TVOCs), and specifically, cumene, exceed “Acute Exposure Guideline Levels” (AEGLs). However, there is no stop work condition for odors. And the table below is the only reference in the plan to shutting down when TVOC emissions exceed those levels.
The next section, titled “Alert and Action Level Response Plan,” lays out the responses when emissions and odors at levels specified in tables four and seven above. Those include implementing control and mitigation measures “in accordance with the Contractor’s Work Plan.”
Ours clarified that “odor intensity is not typically a good indicator of danger level. This is the reason that odors are treated separately and differently in the plan from Total Volatile Organic Compounds (TVOC) which are identified by the photoionization detector (PID). The odor intensity scale is really focused on the level of nuisance, while the PID and gas chromatograph sampling allow for better evaluation of hazard levels.”
He also noted that stopping the work, once under way, is difficult.
“Once the chemical process has started for a given segment of pipe, there is very little that can be done to shut it down,” Ours wrote. “An appropriate response to a high-level pollutant concentration situation might look more like an expansion of the exclusion zone around the work site where people are not authorized to access. If something like this occurs, procedures may need to be re-evaluated for the work on other pipe segments as the project progresses.”
DC Water’s Elledge, at the December ANC 3F meeting, suggested that controlling and mitigating leaks might include letting the work continue.
The resin “off-gases while it’s in that liquid form so really what we’re trying to do is get it to a solid state as quickly as possible,” Elledge said. “Once the heat has started, the best way to limit any additional emission would be to actually continue the curing process.”