The Pennsylvania Environmental Council (PEC) respectfully submits these comments to the Pittsburgh Water and Sewer Authority (“PWSA”) on the City of Pittsburgh and PWSA Draft City-Wide Green First Plan (“Plan”).
In making these comments, we are, once again, reminded that the challenges of addressing wet weather flows in Allegheny County and, more specifically, the ALCOSAN service territory, are exacerbated by the fragmented set of jurisdictions and responsibilities within the county when it comes to dealing with managing water. As a result, a number of our observations go beyond the City of Pittsburgh and PWSA boundaries and identify needed steps that include ALCOSAN and other municipalities.
Through work across Pennsylvania, PEC supports the effective deployment of green stormwater infrastructure to improve water quality and mitigate flood damage to the built and natural environments. We have a long history of participation in policy initiatives and demonstration projects that promote the use of green infrastructure throughout the Commonwealth. For example, PEC has been involved in:
- Conceiving the Pennsylvania nutrient credit trading market in the Chesapeake Bay Watershed.
- Managing a widely-acclaimed stream restoration demonstration project known as the “Big Spring Run Legacy Sediment Removal and Aquatic Ecosystem Restoration Project” in West Lampeter Township, Lancaster County.
- Managing a grant for a successful stream buffer project known as the “Lancaster General Hospital Riparian Buffer Project in East Hempfield Township, Lancaster County.
- Engaging in a variety of watershed restoration and green infrastructure projects, education and outreach, and water quality monitoring programs including the Philadelphia Water Department’s Green City, Clean Waters green infrastructure program; the William Penn Foundation’s Delaware River Watershed Initiative and related Upstream Suburban Philadelphia Cluster, the Watershed Alliance of Southeastern Pennsylvania, and the Wissahickon Watershed Water Quality Improvement Plant.
- Leading a variety of green infrastructure demonstration projects in western Pennsylvania including in the city of Meadville, Ohiopyle Borough, and Etna Borough.
In Allegheny County, PEC has partnered with 3 Rivers Wet Weather on a number of projects including participation as a stakeholder in the ALCOSAN Sewer Regionalization Evaluation Review Panel and the follow-on Sewer Regionalization Implementation Committee. We are also a stakeholder in the RAND “Resilient Stormwater Management” pilot study for Pittsburgh. Finally, PEC has participated in numerous ad hoc discussions with other stakeholders on issues such as the establishment of a stormwater utility and collaborative processes for the development of a coherent stormwater management plan for the metropolitan Pittsburgh area.
PEC commends the City and PWSA for the initiative taken over the past two years to produce the draft Plan. The Plan presents a vision of what may be conceptually possible to address the impacts of stormwater and captured streams on overflows from the City’s combined sewer system as well as damage to areas prone to flash flooding and sewer backups in buildings. At the same time, the Plan acknowledges the complexity of the endeavor to reliably manage stormwater through green infrastructure and fairly identifies the significant details that require further investigation and evaluation to determine the feasibility of significant aspects of the Plan.
The Plan also acknowledges that, even if one of the three ALCOSAN system configurations proposed proves feasible and effective as implemented, the annual volume of sewer overflows will only be reduced by 30 percent to 50 percent. In other words, the PWSA’s Green First Plan, while it may prove to be effective for the combined sewer system in the City, will not, in and of itself, be sufficient as a regional solution, particularly in the separate sewer systems where the overwhelming source of extraneous water is groundwater, not rainfall. It is incumbent upon PWSA to: work first with ALCOSAN to determine as promptly as possible if one or more of the proposed system configurations will perform as predicted; and, second, to constructively engage with the other municipalities in the ALCOSAN service territory as well as other community stakeholders, to collectively build a coherent plan for effectively addressing the varying sources of extraneous water in the collection and conveyance systems throughout the ALCOSAN service territory. These actions must be accomplished before the initiation of the design phase of the source reduction projects to be constructed pursuant to the revised federal consent decree being negotiated.
It is beyond the scope of these comments to critique the conversion of the ALCOSAN basin- scale hydrologic & hydraulic model to an updated system-wide model or the underlying cost calculations incorporated in the draft Green First Plan. PEC believes that, at this stage, such effort is better left to those who have more experience and expertise in such evaluation and we will look forward with interest to see the comments of others on the quantitative aspects of the Plan.
Rather, the focus of these comments is on the process going forward. It is now time that the decision-makers of the parties that contribute to the operation of the ALCOSAN system engage in a concerted effort to formulate a coherent plan for metropolitan Pittsburgh that effectively incorporates green infrastructure and other source reduction mechanisms together with right- sized gray storage, conveyance, and treatment infrastructure to improve water quality for the region.
The Plan, as it should, focuses on a solution to the challenges posed by the City’s combined sewer system that, for the most part, cannot be replaced. The strategic deployment of green infrastructure as a source reduction methodology in the City (and certain other municipalities in the core of the ALCOSAN service territory that are served by combined sewers) is likely to be a cost-effective component of a plan to comply with federal, state, and county clean water requirements. As the Plan acknowledges, the successful, long-term implementation of a green infrastructure strategy is more complex than reliance upon gray infrastructure. However, the triple-bottom-line co-benefits make the effort worthwhile. It is PEC’s sense that not every element of the Plan will, upon further evaluation, prove to be feasible or cost effective. Nonetheless, it is also our expectation that, once the further feasibility and cost evaluations are completed, green infrastructure will and should be a major component of PWSA’s contribution to the solution for the sewer overflow problem in the ALCOSAN service territory.
It is imperative, to the extent the Green First Plan relies upon actions by ALCOSAN (e.g. the operation of the treatment plant wet well at a reduced hydraulic grade line level, removal of sediment from the existing interceptor tunnels, and modification of tipping gate settings at certain regulator structures), that PWSA and ALCOSAN complete their joint feasibility evaluation as promptly as possible and modify the Plan as appropriate and necessary.
Because the Plan is appropriately focused on the deployment of surface green infrastructure to manage stormwater and remove the inflow of captured streams from the combined sewer system, it does not address the largest source of extraneous flow in the ALCOSAN conveyance system–groundwater. PEC understands that, of the approximately 80 billion gallons of flow that enters the ALCOSAN collection and conveyance system annually, approximately 22.5 billion gallons is sewage, approximately 7.5 billion gallons is stormwater, approximately 40 billion gallons is groundwater infiltration and approximately 9 to 10 billion gallons is discharged as untreated overflow prior to reaching the Woods Run treatment plant. While surface green infrastructure installations will be an effective component of an overflow mitigation plan in the less than 20 percent of the ALCOSAN service territory served by combined sewers, it will be far less effective in the over 80 percent of the ALCOSAN system served by separate sewer systems where groundwater infiltration is the predominant source of extraneous water.
Over the past 12 to 18 months, other municipalities in the ALCOSAN service territory have also been reviewing source reduction pilot projects for purposes of complying with administrative consent orders executed in the fall of 2015. The reports on the outcomes of these municipal source reduction pilot programs are due to be submitted on or before December 1, 2017. PEC understands that to a large extent these municipal pilot projects are focused on various approaches for mitigating groundwater infiltration. In addition, ALCOSAN is continuing with its due diligence for the acquisition of multi-municipal trunk sewers in accordance with the transactional framework recommended by the Sewer Regionalization Implementation Committee. These endeavors will identify other key components of an ALCOSAN system-wide wet weather compliance plan.
PEC believes that the information being gathered and evaluated through the performance of these disparate source reduction assessments will provide the best opportunity ever for the parties that contribute to the operation of the ALCOSAN collection, conveyance system to formulate a coherent system-wide plan for effectively mitigating sewer overflows and improve water quality in metropolitan Pittsburgh. However, we anticipate that the various components of a system-wide plan will compete with each other for priority in the sequence of implementation and, perhaps, for available funding. Consequently, it is imperative that the parties convene soon to establish a framework for reconciling competing components of the plan that will be implemented to meet the requirements of the modified federal consent decree.
PEC further believes that the process for finalizing the elements of the wet weather plan should include ample opportunity for meaningful stakeholder participation.
Again, we commend the City of Pittsburgh and PWSA for the Plan and look forward to working with them and many others to identify wet weather solutions across the region and how best to integrate green infrastructure, source reduction, and other strategies into those solutions.