Last week, the Buffalo Sewer Authority presented residents of the neighborhood south of Forest between Elmwood and Grant with details of an experimental plan to mitigate combined sewer overflows—that is, untreated sewage flushed into area waterways when heavy rain overwhelms the city’s sewer system—by creating a retention chamber with computer-controlled dam gates in part of the system that runs under Bird Avenue.

A similar project is planned for Lang Avenue on the East Side. Both projects necessitate lengthy street shutdowns and traffic redirection. They are part of a comprehensive plan to bring the city’s sewer system into compliance with the federal Clean Water Act, which the city has violated for decades, thanks to an antiquated system that accepts wastewater and stormwater into the same tunnels. It’s a huge, unwieldy, and expensive pollution problem, and Buffalo is hardly the only aging Northeastern city subject to a consent order from the US Environmental Protection Agency to address the issue.

West Side community and environmental activist Charley Tarr is sympathetic to the goals of the BSA’s Long Term Control Plan to address combined sewer overflows, but he’s concerned that the $4 million vault-and-valve projects proposed for Bird and Lang avenues pose a serious risk to residents. On Tuesday, he sent a letter to Buffalo’s Corporation Counsel, Tim Ball, and the Buffalo Sewer Authority’s David Comerford, asking them to hold off on shutting down streets surrounding the two projects and beginning construction, pending further study and public hearings.

Among the concerns Tarr listed in his letter to Ball and Comerford are these:

• The EPA identifies 115 organic compounds (including volatiles) and 14 metals as “priority pollutants” in combined sewage. If the system fails, he writes, that pollutant-laden sewage might back up into resident’s basements.

• The project is titled and repeatedly described as a “demonstration project.” During the recent community meeting the phrases “emerging technology” and “experimental technology” were used.

• When BSA’s Long Term Control Plan was first rolled out at community meetings in 2012, retention projects such as this one were not specifically described. “My neighbors…agree with my recollection that during that time period the process of retention was described as an ‘Emerging Technology’ and it was continually described as a ‘grey’ (concrete) solution involving the construction of tank (retention) infrastructure in an industrial area of the city,” Tarr writes. “Several neighbors recall that acquiring the vacant Squib Pharmaceutical property for this purpose was discussed as the slide was presented.” Because these projects were not specifically described previously, Tarr argues, they must now be subjected to environmental reviews to make certain that they’ll work and that the neighborhood will be protected from any negative impacts.

• Tarr worries that retaining raw sewage in a vault will cause pollutants to settle out at the bottom of that vault, and cites state guidelines requiring regular and adequate flushing of such retention areas. He says that city officials have not adequately addressed that concern. Right now, for better or for worse, stormwater flushes the 19th-century brick sewage chamber underneath Bird Avenue.

• Further, he writes:

BSA officials attending the meeting identified the intention to dam the combined sanitary and storm sewage to a slurry height of approximately 28-feet during a rain event. They further described retaining this slurry across a distance of more than 10 city blocks toward a goal of “maximum retention” based on hydraulic calculations. Mr. Paul McGarvey an engineer with GHD asked to identify that the sewer will not be dammed completely closed. Mr. McGarvey indicated that the gates are intended to be open enough to create a bottom flow slightly larger than mean calculations for the daily flow of blackwater…

In the absence of review, it is not being considered that during storm events, as the sewer is repeatedly dammed in the proposed manner, combined sewage will be raised to unprecedented heights on the sides of the 19th Century oval brick chamber walls. This will leave a ‘scum coat’ of bacteria and toxic contamination on a substantially enlarged surface area in the chamber. The traditional rushing motion of storm water that has previously ‘cleansed’ the brick and masonry of ‘scum coat’ contamination on (formerly) lower levels will be all but completely eliminated. Horrendous odor and impacts on health are thereby a grave and valid concern…

In the absence of review, the hydraulic calculations assuring that basements will not be flooded with sewage appear arbitrary. It was revealed in the March 11th community meeting that the present calculations are based on the dimensions of a clean and clear-bottom sewer chamber. Unfortunately, the process of repeatedly damming & releasing large volumes of combined sewage slurry is guaranteed to drop sediment and solids, forming a delta. This principle can be witnessed by viewing the large ‘island’ of fecal solids in Scajaquada Creek at the edge of the reflecting pool near the Historical Society building…This variably sized delta of solids will dramatically impact the dimensions of the interior of the sewer. Calculations against system failure and flooding into residential basements are then unreliable and arbitrary. Horrendous odor and impacts on health within the home are again a grave and valid concern…

Tarr goes on to argue that, before undertaking such a project, BSA is obligated to study the condition and capacity not only of city-owned sewer infrastructure but of the tie-ins to residents’ houses, many of which are more than 100 years old. He argues that BSA has yet to present any evidence that they’ve studied the traffic impacts during the construction project, as well as impacts to the streetscape, among other consequences.

All of these impacts would be considered under the process prescribed by the State Environmental Quality Review Act, which he argues has not been applied to these specific projects. Tarr says he recognizes that mitigation of the city’s sewer problems is a good and necessary thing. However, he writes:

[I]t is invalid to attempt to include in this broad concept review any declaration as to the impact of individual construction projects, simply because, as a whole there will be a ‘dramatic betterment’ if the Buffalo Sewer Authority succeeds in is intention to ultimately comply with an EPA order. The ‘betterment’ and ‘public good’ of compliance is fully separate from the review of proposed solutions required by SEQRA. The State Environmental Quality Review Act demands consideration of the exact impact and public suffering of various engineered solutions toward the larger compliance. The process of Environmental Impact Study is the mechanism by which these impacts are properly weighed; allowing good solutions to be sorted apart from bad ideas.

We’ll post Tarr’s full letter and further documents regarding the two projects on AV Daily at Artvoice.com.