CRWA began what we call our Urban Smart Sewer project in the fall of 2013 with a three year grant from the Scherman Foundation's Rosin Fund, and support from Eaglemere Foundation. Our first orders of business were to discover whether the distributed wastewater treatment plants we had investigated with our Littleton, MA, Smart Sewer project could be sited in dense urban confines. To help us, we put together a technical advisory committee (TAC) made up of principals from federal, state, and Boston agencies.
Some encouraged us to look for sites on existing institutional campuses where available space and predilection might afford us early success. I resisted that notion for several reasons. I believe that institutions with the desire to address energy, water, and climate issues in construction and reconstruction are likely to pursue distributed wastewater and energy on their own as they understand the options. Even better, they are likely in such pursuit to bring a wealth of creativity and insight to their endeavors. CRWA does not own the how, nor do we own the why, other than to make a compelling case for transformation.
Moreover, if we are to truly transform, then it is essential to demonstrate that resource recovery plants, and green infrastructure can be incorporated into dense, challenging locations. It would simply not be good enough, in my estimation, to locate a few such plants as curiosities on a few institutional campuses, although we welcome them to join our cause.
Finally, as part of our grant submission to Scherman, we were interested in investigating the opportunities and challenges with siting a plant and its associated green infrastructure in an environmental justice community. Promoting and Supporting Rich Diversity extends to all species, including us. Communities historically suffering the most from the pitfalls of traditional infrastructure should be among the first included in our approach and its benefits.
We began by assembling the necessary elements to support a plant. We focused on a small “district” scale which would be served by a small-scale wastewater treatment and resource recovery plant with resources returned to the community for use in the district. Our team determined a district scale approach was preferred over a direct site level identification, as relevant sources for inputs (sewage and food waste) could be considered in conjunction with sinks (energy and water users), while also considering the environmental needs of a particular area.
|Urban Smart Sewer initial study area. (expand map)
Our two pilot districts were to be served by resources recovered from between one and five million gallons of wastewater daily. They therefore needed to be located near sewer interceptors (i.e., the biggest sewer pipes) so that they could mine wastewater from existing infrastructure. They needed to be located near major thoroughfares so that trucks bringing in food waste to enhance methane production wouldn’t have to drive down residential streets (alternatively, however, close proximity to a high density of food waste producers - restaurants, universities, food processors - may make transport via smaller vehicles more practical, efficient, and neighborhood and environmentally friendly). They needed to include potential customers for electricity, thermal heating and cooling, and reclaimed water. They needed to present opportunities for linked green infrastructure or desirable soil conditions where treated effluent would ultimately be discharged.
We began our search for potential districts by first identifying the densest cities in Massachusetts: Boston, Cambridge, Chelsea, Somerville, Everett, and Malden. Together, they made our initial study area.
We put together a matrix of necessary elements, and using GIS, identified initially over 30 potential districts in the six cities. After refinement, we reduced that number to 23. I’ll be honest; I was relieved we had so many options. It would have been embarrassing, to say the least, to get our project funded and then discover we had very few opportunities.
Of these 23 districts, with insights from members of our TAC, we selected two for our initial feasibility study.