March 28, 2018
Robin Johnson
U.S. EPA – Region 1
5 Post Office Square, Suite 100
Boston MA 02109-3912
Subject: Spencer Wastewater Treatment Plant draft NPDES Permit
Permit Number: MA0100919, Public notice MA-009-18
Dear Ms. Johnson,
I am submitting comments on the draft National Pollutant Discharge Elimination System (NPDES) permit for the Spencer Wastewater Treatment Plant (WWTP) on behalf of the Connecticut River Conservancy, formerly the Connecticut River Watershed Council. The facility discharges to the Cranberry River, which discharges to the Sevenmile River, which flows to Quaboag Pond, then to the Quaboag River, to the Chicopee River, and then the Connecticut River. Qauboag Pond is also connected to Quacumquasit Pond. Cranberry River and Sevenmile River are not known to be water-quality impaired, but there is a Phosphorus TMDL for Quaboag and Quacumquasit Ponds (MassDEP report MA36130-2005-1, CN 216.1) dated May 2006. All permits in the Connecticut River watershed fall under the Long Island Sound Nitrogen TMDL. We are interested in improving water quality in the Connecticut River and its tributaries such that they can all one day meet Class B water quality standards.
CRC attended the public meeting and hearing held at the public library in Spencer on Monday, March 26, 2018. At the time, we asked several questions but did not present comments. We obtained a copy of the Potential Plant Upgrade Process Flow Diagram at the meeting. Our comments are below.
- The 7Q10 and dilution ratio may not be conservative enough
EPA has calculated the 7Q10 (lowest observed mean river flow for 7 consecutive days, recorded over a 10-year recurrence interval) for the ungauged Cranberry River on extrapolated data from the most recent 30 years at a station in the nearby Sevenmile River in Spencer. EPA has considered topography, drainage area, land uses, proximity, and nearby water supply wells, and considers the drainage areas qualitatively similar enough. CRC consulted with MassDEP’s interactive online map built as part of the Sustainable Water Management Initiative (SWMI). According to this tool (linked at https://www.mass.gov/guides/sustainable-water-management-swmi-technical-resources), the Cranberry River watershed is in the pink groundwater category (category 4) and is >25-50% flow impacted. The Sevenmile River watershed upstream of the Cranberry River is yellow (category 3), and is >10-25% flow impacted. Cranberry River sub-basin is coded as a “yes” for >25 groundwater depletion, whereas Sevenmile River is not. For fluvial fish, the Cranberry River basin is the highest category of alteration, 5, and is >65% impacted. Sevenmile River is category 4, or >25-65% altered.
Using the Sevenmile River flows as a surrogate for the Cranberry River may not be conservative enough, and CRC recommends that some kind of calculation be developed to account for the Cranberry River’s higher level of impact from groundwater withdrawals. This would potentially then impact permit limits.
- Additional sampling should be required to ensure permit limits are met
Given the high volume of seepage through the wetland beds (~50% or more influent lost), additional sampling should be required to ensure that permit limits are met for this unusual facility. The effluent should be sampled as is required in the current and proposed permit. But sampling should also be required upstream of the facility on Cranberry Brook, and just upstream of the confluence with the Sevenmile River, ideally on a weekly basis. Should the potential facility upgrade be constructed, this requirement could be eliminated.
- Total Nitrogen (TN)
The draft permit section I.B.1. requires that the permittee complete an evaluation of alternative methods of operating the existing wastewater permit to optimize nitrogen removal, setting the baseline mass loading for the facility at 86.2 lbs/day. The Fact Sheet on page 21 explains that the Long Island Sound Nitrogen TMDL baseline analysis for the Spencer WWTP was 63.5 lbs/day based on an average flow that did not take into account effluent flow lost through the wetland beds. Because of this error, the plant is getting a 36% increase in their loading limit! CRC does not understand why loading limits for TN have been based on current flows and not design flows, as is done for TSS and BOD.
CRC recommends that the permit be revised to include two optimization requirements: 1) an optimization study for reducing N in the interim prior to plant upgrade, and 2) N reduction options for the potential plant upgrade presented at the public meeting. There should be two separate due dates established for these efforts.
CRC requests that EPA establish annual load limit for TN that is enforceable.
CRC supports the proposed ammonia-nitrogen limits, which unlike the TN limit, are appropriately based on design flow.
- Total phosphorus (TP)
CRC again does not understand why the TMDL for TP was based on average flows rather than the design flows.
EPA should establish enforceable deadlines to the potential WWTP upgrade, requiring that the upgrade happen in the quickest achievable time frame. This could be accomplished in the permit, or in a separate enforcement order, which would also make it clear that the existing permit authorizes discharge through outfall 001, not the wetland beds. We agree with the comments dated March 19, 2018, submitted by James P. Vander Salm, attorney for the Quaboag-Quacumquasit Lake Association (“QQLA letter”) that the EPA and MassDEP have given the permittee a long time to tackle this already. The 2006 TMDL on page 44 said that a feasibility study to meet the TMDL limits was in the works at that time, 12 years ago. Giving the permittee until 2024, the entire life of the upcoming permit, and 18 years after a feasibility study, is too long a time frame.
CRC concurs with the QQLA letter that the TP seasonal limits should be in place for the period April 1 – October 31. Additionally, we request that dissolved orthophosphorus monitoring be required during the winter months, for the same reason it is required in the Belchertown MA permit.
Typically, interim and final limits are shown separately in the table at 1.A.1. The draft permit only lists the new total phosphorus limits, and a reader needs to refer to Section 1.B.2 to find out those limits won’t go into effect until the end of 2024.
CRC generally endorses all of the comments in the QQLA letter and those submitted by Chicopee4Rivers Watershed Council.
- Progress to reduce infiltration and inflow (I/I) should be further along
The current 2007 permit required an I/I report due in March 2008, then annual reports. At the public meeting, the permittee described a MassDEP-required I/I report nearing completion. Given that the current permit already required significant I/I work, we can’t figure out why there is no mention of the progress made to date in the Fact Sheet. Has the town made sufficient progress to reduce unnecessary inflows in the last 11 years?
CRC appreciates the opportunity to provide comments on the draft permit. I can be reached at adonlon@ctriver.org or (413) 772-2020 x.205.
Sincerely,
Andrea F. Donlon
River Steward
Cc: Susannah King, MassDEP
Keith Davies, Chicopee4Rivers
Doug Vizard, QQLA
Denise Ruzicka, CT DEEP
