Members: Interim Chairman Paul Lauenstein, David Hearne, David Crosby, and David Ferestien
Others: DPW Superintendent Eric Hooper, Selectman Joe Roach, Selectman Richard Powell, Town Administrator Ben Puritz
Interim Chairman Paul Lauenstein deferred discussion of the minutes of February 15 because many of those who were in attendance at that meeting were absent on February 27.
Paul Lauenstein wrote a set of recommendations to the water commissioners for discussion. David Hearne wrote extensive revisions to Paul Lauenstein’s original version. It was decided to use David Hearne’s version as the basis for discussion.
The committee reviewed David Hearne’s recommendations, made alterations, and voted unanimously to submit the edited version to the water commissioners. The document is appended below.
A motion was made and seconded for the WMAC to support the South Main Street commercial rezoning article. Paul Lauenstein expressed his opinion that it is inappropriate to undertake massive development in a sensitive groundwater protection district and that the committee was insufficiently informed to pass judgement. David Hearne countered that the town would have more control and recourse with a commercial real estate company with deep pockets than individual homeowners.
This motion passed 3 in favor, 1 opposed.
Sharon CFII L.P. (the “developer”) has proposed a 450,000 square foot “Lifestyle Mall” with parking capacity for 2,000 cars on a 57-acre parcel of land off South Main Street, located in a groundwater protection district, which includes wetlands. Impervious surfaces would cover approximately 37 acres. This development would be located within the recharge area of two wells, #5 and #7, that supply about 30% of Sharon’s current water use. The development estimates water needs associated with this zoning change to be approximately 60,000 gallons per day, or about 3.4% of Sharon’s permitted water use.
A Special Town Meeting has been called for March 12 to vote on the question of commercial re-zoning of this parcel of land. It is important that the Board of Selectmen (BOS) consider issues associated with both water quality and quantity in their deliberations regarding this zoning change.
The effects on the wells in the sub-basin posed by commercial development can be partitioned into three components:
A. Discharge from on-site wastewater treatment plant (WWTP)
B. Storm water runoff
C. Aquifer recharge
A. Discharge from on-site wastewater treatment plant (WWTP)
The developer has proposed an on site WWTP with a capacity sufficient to treat and discharge all waste generated from development associated with this zoning change, as well planned subsequent residential development. The developer is also donating to the Town of Sharon approximately 11 acres as a potential site for a future production well. The WWTP is expected to be located in the northeast corner of the lot, presumably within the Zone II of Well #5. It would be approx. 2,000 feet from the proposed new well and approx. 6,000 feet from Sharon’s Well #5.
It is important for the BOS to understand that a WWTP can in and of itself, become a source for concentrated site contamination and potential contamination of Wells #5 and #7 and this possible risk must be weighed against any possible benefits to the town associated with this zoning change. Although effluent from the WWTP is required to meet state standards for drinking quality water, the BOS should be concerned with the long term effects of nitrate injection into the aquifer. The BOS should consider the fact that state standards allow effluent levels up to 10 ppm of nitrate. The WMAC strongly recommends that the MOU include the expectation that any effluent from the WWTP meet any future standards. It is also strongly recommended that the MOU outline the expectation for a system of monitoring wells that surround any effluent discharge, location of which is to be determined through the Ground Water Discharge permitting process. The burden of operation and maintenance of the system is to be born by the developer or his agent in perpetuity. The Developer should be required to post a bond in order to guarantee funding of such future operational requirements. The approval process should specify what contaminants would be monitored and how frequently they would be sampled. The WMAC recommends that the approval require a contingency plan, approved by the Massachusetts Department of Environmental Protection, in case groundwater contamination is detected.
It is reasonable that the BOS also consider the risks of well contamination associated with this zoning change and the on site WWTP relative to the potential risks associated with an alternative residential development of this site under its current zoning allowance of 60,000 sqft. lots.
Under the zoning change, effluent would be concentrated, treated and monitored. Under current zoning, residential effluent would be decentralized, treated through a passive, lot specific septic distribution system, and unmonitored. Issues of nitrate control, the primary concern associated with residential septic effluent, would be beyond the reach of the BOS, as would control of any potential run off from lawn treatment, residential pesticides use, and whatever household cleaners and solvents may inadvertently make their way down a drain. All would enter the aquifer directly, untreated and unmonitored in any way.
B. Storm water runoff
Storm water runoff associated with the impervious areas within this development should be of signifigant concern to the BOS. Of primary concern should be the systems associated with run off from parking areas, and areas of traffic control at intersections as these areas will be both the predictable source of contaminants, as well as the most probable location of a “worst case” contamination by chemical spill. Both the quality and quantity of this run off need to be considered.
Concerns about the quality of storm water runoff can be focused on containment and treatment of solids and soluble contaminants. Current standards require that 80% of the suspended solids and oil-based contaminants be removed prior to discharging storm water to leach fields or vegetated infiltration areas. They also require that filters be properly maintained according to Massachusetts Department of Environmental Protection (DEP) practices. Soluble contaminants associated with the development would not removed by the filters, but such contaminants are the most likely source of well contamination. Provision should be made for long-term maintenance and monitoring of all run off from storm water catch basins, associated leaching fields and vegetated infiltration areas to maintain their effectiveness.
Given the sensitive nature inherent in the water protection district, the BOS should require the same standards of treatment and monitoring for all catch basin collection at any and all traffic control infrastructures associated with this zoning change as is standard for the parking areas. Traffic infrastructure changes are planned for purpose of egress and control. Design of the storm water management plan for these areas should be integrated with the overall development plan for purposes of monitoring and treatment.
The quantity of storm water runoff should also be of concern for the BOS. Compliance with the storm water provisions of Sharon’s bylaws during construction, as well as the Department of Environmental Protection’s Storm Water Management Policy after construction, is mandatory.
C. Aquifer recharge
The site design of the new commercial development must, by state standard, recharge at least as much storm water run off as recharges in the pre-construction condition with respect to the peak rate of storm water runoff for a ten-year frequency storm event, as well as the total volume of storm water runoff for a one-year frequency storm event. Although existing rates of infiltration throughout the 57 acres have yet to be analyzed, it has been represented to the WMAC by the developer that they will strive to exceed predevelopment rates of infiltration. If such increased rates of recharge cannot be achieved on site, the developer is committed to offsite efforts of mitigation to achieve greater than existing rates of recharge for wells #5 and #7.
The WMAC would also advise the BOS to bear in mind the potential for future costs to the Town associated with all aspects of the oversight of this zoning change associated with issues of monitoring and compliance enforcement. Additional funding of town staff may be required and associated costs should be considered.
In consideration of the limited water resources of the Town of Sharon, the developer has offered to offset the additional demand of the development by a combination of increasing the amount of “surplus” storm water recharged on site beyond the amount that naturally recharges under pre-construction conditions, and helping reduce water use elsewhere in the community. The developer has also offered to fund efforts at water conservation town wide.
4. Main Replacement
The developer has offered to replace the existing 8” water main on Old Post Road with a 12” main, and create a service loop through the new development, connecting with the existing water main on South Main Street.
5. New well
Few sites remain in Sharon that would be suitable for a municipal well. Preliminary testing of the site to be donated to the Town by the developer has proven to be reasonable as a secondary source for a production well.
The site in question lies within the Zone II of two Town wells that are a significant source of water production for the Town of Sharon. Such areas warrant special protection. Any development in a groundwater protection district must be carefully considered and any potential risk to our ground water sources be monitored and safeguarded to the greatest extent possible. The proposed commercial re-zoning of this land does present risks to the water quality of the wells downstream. But there are also risks posed to those same well sites under our current zoning of this land. It is crucial that the Board of Selectmen, the Board of Health, the Conservation Commission and the Zoning Board of Appeals develop and manage the permitting process carefully with respect to issues of water management. Successful management of this process can ultimately benefit the very resource we seek to guard and preserve, our most valuable resource, our water.