WPCA October 23, 2003 Minutes

The following WPCA members were present:
Joseph Lauria, Chairman; Gary Zawacki, Ron Hill.
Kevin Briody was absent.

Other Attendees:

Max Caldwell
OMI	Carey Strout, Mark Kajka
Metcalf & Eddy:	Jon Pearson

Meeting was called to order at 7:00 p.m.

1) Approval of Minutes

a) . Approval of the Minutes from the September 2003 was tabled until the next meeting.

2) New Business

Jon Pearson, Metcalf & Eddy

1. Middle School Pump Station and Force Main
— Punch List is not complete. Expect completion by next meeting.
2. Fox Hill Construction easements discussed.
— Mr. Pearson will discuss Fox Hill contract with purchasing department for bid. First invoice for design work paid by Fox Hill Condominium Association.
3. Amendment for engineering services in connection with the evaluation of modifications to the HVAC systems at the Headwork's Building at the South Street Treatment Plant was presented and signed by Mr. Lauria.
4. Authorized M&E to go forward with the additional work with hydrant, roof repair at the Route 7 facility.
5. Authorized M&E to start on the South Street WWTF NPDES permit.

a) South Street Influent Pump Station

1. Mr. Pearson noted at last months WPCA meeting, regarding a concern about the capacity of the influent pump station at the South Street plant. Since the last meeting, M&E has reviewed the capacity requirements for the pump station. With the redirection of flow from the Fox Hill condominiums, and the proposed increase in capacity of the Copps Hill pump station, the capacity of the influent pump station at the plant needs to be increased to accommodate the influent peak flow rate of 680 gallons per minute (gpm). The influent pump station wet well was planned to be replaced to address deterioration due to chemical attack of the concrete structure from hydrogen sulfide. M&E considered three options to increase the capacity. The first option involves keeping the existing pumps and installing a larger wet well. The existing wet well is 8 feet in diameter, and a 10-foot diameter well would be provided. The existing pumps would be removed and reinstalled in the new wet well. This would allow the influent pump station to accept the flow volume from one cycle of the Copps Hill station. The larger wet well will provide additional storage of the incoming flow, and does not increase the flow rate to the plant as the existing 290 gpm pumps would be retained. The major concern with this option is that if, under high groundwater and storm conditions, the peak flow at the Copps Hill station persists for an extended period, the increased volume would exceed the influent pump station capacity. The existing collection system has a history of Infiltration/Inflow impacts, and for this reason, this option is not recommended.

2. The second option involves replacing the existing pumps with larger, constant speed pumps sized for the 680 gpm influent flow in an 8-foot diameter wet well. Under this option, the wet well, valve chamber, pumps, and controls would be replaced. This option provides the needed capacity to accommodate the influent flow rate, but has the disadvantage of increasing the influent flow rate into the plant. Regardless of the flow into the pump station, the pumps would discharge 680 gpm into the plant headworks. The existing pumps discharge at a rate of 290 gpm, and the larger pumps would likely result in flow surges, potentially impact downstream treatment processes. For this reason, this option is not recommended.

3. The third option involves replacing the existing pumps with larger pumps in an 8-foot diameter wet well, with the pumps equipped with variable speed drives. This would allow the pumps to discharge at a rate, which matches the incoming rate. Under this option, the wet well, valve chamber, pump sand controls would be replaced. This will require a system to monitor the wet well level and control the speed of the pumps. A submersible pressure transducer and a programmable controller system would be provided. This is the recommended option. M&E estimates that the construction cost for this option, based on the concept as discussed, is approximately $375,000. Based on a review of the current budget for the pump station rehabilitation project, the estimated cost for the design of this option is $40,000. Assuming no new survey is required, and that the existing boring data for the South Street plant upgrade are available, there are sufficient funds available in the project design budget for this work.

4. There was discussion regarding the need to replace the pumps, given their problematic history, and that they were installed in the early 1990s. The WPCA questioned the estimated construction cost, as it appears to be a very conservative estimate. M&E will provide a cost breakdown supporting the estimated construction cost. OMI expressed concern over increasing the level of complexity of the pump control using variable frequency drives and controls. OMI was not familiar with the submersible level transducer. M&E will provide literature on the equipment to OMI.

3) OMI Report

a) OMI Monthly Report discussed in detail.
b) Mr. Strout stated OMI suspects grease being released into manholes in the Ramapoo area.
c) Volute Ni-Hard Impeller, bolts and washers needs to be replaced.
Motion to approve purchase Smith & Loveless parts to replace volute from J&R Engineering for $6,500 by Mr. Hill and seconded by Mr. Zawacki, passing unanimously.
d) Excessive use of water bill for septic hauler's use was presented for WPCA payment for $2,400 to OMI.
Motion to approve payment to OMI for $2,400 for water bill by Mr. Hill and seconded by Mr. Zawacki, passing unanimously.
e) Excessive amounts of grease has been reported in the collection system from Lotus restaurant. This has been a problem in the past and Mr. Lauria will write a letter to the owner of the restaurant requesting reimbursement of grease removal by OMI.
f) Generator repair and maintenance was discussed. Mr. Lauria suggested Mr. Strout check on prices in generator repair quote.
g) OMI addressed a letter written by Charles Fisher, Town Engineer, stating his dissatisfaction with the procedures taken by OMI in response to a recent backup. OMI stated that a new procedure was in place to rectify the response time. OMI also requested an information flyer be sent to sewer use users in proper care and maintenance of the sewer system.
h) OMI stated that there are two trees that need attention on the properties. WPCA will contact Mr. Pinchbeck, Town Tree Warden for tree removal.

4) Adjournment
Motion to adjourn at 8:07 by Mr. Zawacki seconded by Mr. Hill. Passed unanimously.

Respectively submitted
Diana Van Ness