At the public meeting this Wednesday on the Soapstone Valley sewer rehabilitation project, at least one member of the community will be asking the National Park Service and DC Water if the work has to be so invasive.
As described on page 6 of Appendix E, Statement of Findings:
Approximately 6,100 [linear feet] of sanitary sewer pipe infrastructure within the Soapstone Valley sewer system would be rehabilitated using trenchless technology…. Cured-in-Place Pipe (CIPP) is a trenchless rehabilitation technology that involves the insertion of a resin-impregnated felt lining inside the existing, or host, pipe. This lining is then cured in place using either water or steam…. With this technology, most construction activity occurs at existing manholes. Given the site constraints in the study area, construction of access paths to certain manholes would be necessary.
The Statement of Findings goes on to state that paths will be required for heavy equipment access. They will be 16 feet wide, but at some locations, the paths will be wider than 20 feet to allow for maneuvering the equipment.
Marjorie Share, a member of the ANC 3F Parks & Trails Committee, is particularly concerned about the heavy equipment pathways and the resulting loss of as many as 371 trees. (See page 26 of the the environmental assessment, “Impacts of Alternative 2”)
She knew there had to be a better way. She started digging and came across Ultraviolet Cured-in-Place Piping (UV CIPP), or UV curing. This technology does not require the heavy equipment that the steam and hot water curing method does, and thus has a much smaller footprint in hard-to-reach areas like Soapstone Valley. It can also also be a cheaper technology. It is more expensive to do the clearing for the heavy equipment that the steam and hot water method requires.
UV curing was the method used to reline a sewer main in Medicine Lake, Minnesota. The project was led by SEH, an employee-owned engineering, architectural, environmental and planning company in Minnesota that works on infrastructure projects.
Share contacted Dave Hutton of SEH for more information. I was invited to join the conversation.
Hutton told us UV curing technology has been used in the states for about 10 years and in Europe, about 20 years after it was developed in Germany. It has taken a lot longer for the U.S. to embrace this as a go-to trenchless (which means not digging up pipes to replace them) technology.
Hutton said the Medicine Lake project involved sewers situated between the lake and people’s homes, “so it would have been pretty much impossible to get the steam/hot water equipment back to the manholes,” Hutton said. “The UV cure method and equipment was a great solution to line the sewers in this very difficult conditions. It was the first UV cure liner used for a City in Minnesota and I was very impressed with the technology and process and would definitely consider using it again with the right project and circumstances.”
J.C. Dillon of Peoria, Illinois was the contractor SEH used for the Medicine Lake project. Hutton told us there about 10 companies around the country that do this work.
The public meeting on the Soapstone project will be held on Wednesday, June 26th, 6 to 8 p.m. at the Forest Hills of DC Assembly Hall (4901 Connecticut Avenue). Marjorie Share and others will be eager to hear whether UV curing or other new technologies could be used in the Soapstone Valley.
Kathy Pickens says
Anything at all that can be done without decimating our beautiful forest would be more than preferable to all of us who treasure its existence as it is now.
Tony Domenico says
Contracts may have already been issued for the work with the technology already selected, but it would be great if we can convince them to consider a less intrusive method.
It would be a shame to lose so many trees.
Green Eyeshades says
I wanted to refute the suggestion that “[c]ontracts may have already been issued for the work with the technology already selected,” but I was not certain whether the National Park Service (NPS) or DC Water (WASA) have actually “selected” any particular technology.
The Environmental Assessment (EA) issued by NPS presents two “alternatives” for the project, but NPS did not yet as far as I know actually “select” either alternative.
To begin to understand the two alternatives, it helps to know the acronym “MS4.” That stands for “Municipal Separate Storm Sewer System.” To DC residents, MS4 may be better understood as the years-long project to divert storm water runoff from the human sewage pipes. For decades, huge rainfalls have overpowered the human sewage system because storm water was dumped directly into the human sewage system. It turns out that DC’s Department of Energy and Environment (DOEE) runs the permits for storm sewer outfalls.
On page 10 of the NPS Environmental Assessment, we are told the following:
“Under Alternative 1, the No Action Alternative, no improvements would be made to the existing sewer infrastructure. This alternative represents the existing condition, which includes the Soapstone Valley sanitary sewer pipes and manholes in varying stages of disrepair; exposed sewer pipes and manholes; and stormwater outfalls in need of repair. Although the sanitary sewer system would continue to degrade, the No Action Alternative represents the existing conditions. The No Action Alternative would not be in compliance with the District’s MS4 permit….
“Under Alternative 2, the Trenchless Alternative, the sanitary sewer system would be rehabilitated in place and would include the following components:
*Trenchless sanitary sewer pipe rehabilitation
*Manhole repair
*Asset (sanitary sewer pipes and manhole) protection and erosion prevention
*MS4 outfall rehabilitation”
Page 12 of the EA states as follows:
“MS4 Outfall Rehabilitation -In January 2012, EPA issued the National Pollutant Discharge Elimination System (NPDES) Permit No. DC0000221, which requires the repair of stormwater outfalls identified as contributing to water quality degradation within the District’s MS4 system. There are two outfalls within the Soapstone Valley Park that require repair, Outfalls F-117 and F-140.”
So, just from those three paragraphs, it is clear that the “MS4 outfall rehabilitation” is just one SMALL part of Alternative Two. Alternative Two does a huge amount more work than the work that would be needed just to fix the MS4 outfall.
From just those portions of the EA, I infer that the “No Action Alternative” could be an acceptable choice as long as it is amended to include whatever limited work is needed to do the “MS4 outfall rehabilitation.” WE DON’T NEED TO KILL 370 TREES JUST TO rehabilitate the MS4 outfall, because there are only TWO MS4 outfalls in the project area.
FHC says
Each option presented in the EA poses risks. If DC Water goes with the steam-cured pipe lining, it poses a potential risk to 370 trees. And if it goes with the no-action alternative, there’s the risk to wildlife when the 110-year-old sewer pipes rupture. It would be nice to find a solution that addresses both issues.
Green Eyeshades says
Thank you for emphasizing the importance of protecting wildlife. Believe it or not, a particular species of wild bat is one of the species that are specifically mentioned in the EA as living in the trees in the project area from April 1 to October. So to protect that species, at least, we need to protect the trees during the bats period of “active” residence in the project area.
The EA states as follows at page 3 (PDF p.9):
“Although not a federally listed species within the proposed project vicinity, NPS has expressed concern over the potential presence of the northern long-eared bat (Myotis septentrionalis). Therefore, NPS consulted with itself for formal Section 7 consultation and concluded that there is no designated critical habitat within the project area. The USFWS does not list the northern long-eared bat within the District as a threatened species; however, NPS has expressed concern over t his species during construction because of required tree removal. The Section 7 consultation identifies conservation measures to protect the habitat during the project. The threatened northern long-eared bat’s active season is from April 1st to October 31st. DC Water and NPS must check with bat researchers on the status of the northern long-eared bat within the park before any trees are removed during the active season.”
At page 28 of the EA (PDF p.34), the impacts on wildlife of the “No Action” alternative are described as having “no direct impacts to wildlife species” and otherwise the impacts are only “minor” in both the short-term and long-term:
“No construction would occur under the No Action Alternative, resulting in no specific change to common aquatic and wildlife habitat and no direct impacts to wildlife species. Soapstone Creek currently does not meet its TMDL targets and experiences high concentrations of E. coli, suspended solids, and other pollutants. Additionally, stormwater flows within Soapstone Creek would continue to convey sediment and pollutants originating from surrounding impervious surfaces and erosion. Therefore, the No Action Alternative would have minor short-term and long-term impacts on wildlife and wildlife habitat, particularly aquatic wildlife habitat.
“Under the No Action Alternative, the sanitary sewer infrastructure would continue to age, and exposed sewer pipes and manholes would continue to be subject to environmental forces including stream flows, stormwater, debris, and human contact. DC Water would continue to inspect and monitor the sewer system infrastructure. Any sanitary sewer system failures would likely result in sewage leaks and would require emergency access to the Park and would be subject to emergency repairs, as regulated by the CWA and the Code of the District of Columbia. Emergency repairs could have an adverse effect on wildlife and wildlife habitat.”
Pat Kasdan says
Many thanks to Marjorie Share for finding a UV-cured sewer lining alternative to the more destructive DC Water/NPS proposal for Soapstone Valley Park.
Pipes may still require cleaning first, which entails closedcircui TV trucks, as well as equipment for by-pass pumping (Appendix E, page 6) and stream diversion pumps (Appendix E, Page 8).
I would prefer to explore the possibility of diverting sewage to existing sewers that run down Albemarle Street from 32nd to 28th Streets, where manhole covers labeled “SEWER” are located at each intersection. This alternative is mentioned as discarded in Appendix D, page 1, with little explanation.