Jim Donchess
Mayor e City of Nashua
To: Board of Aldermen
Filed With: Patricia Piecuch, City Clerk
From: Jim Donchess
Date: December 14, 2017
Re: Digester Facility Boiler System Emergency PO Request
Pursuant to 5-90 (G) of the NRO, | have authorized emergency repair of the boilers at the WW Digester
Building. The repairs will be performed by Johnson Controls of Manchester, NH in an amount of $43,571.
By way of background during routine maintenance to the Digester Facility Boiler systems a
diaphragm failure was discovered in the expansion tanks. This failure caused over
pressurization of the system, resulting in a mechanical seal failure in a water
recirculation pump, damage to the expansion tanks, as well as damage to the water
separation tank.
This failure is believed to be caused by the inconsistent quality of the methane gas
produced by the digester. The current Energy Recovery Generator replacement project,
which is in preliminary design, is already addressing this issue with gas purifying
equipment.
An emergency purchase order on these critical components is needed for three reasons.
First, the boilers are used to heat the digester and are critical to the operation and
maintenance of the optimal temperature of the solids in the digester. Second, the
ordering lead time on some of the needed units is 4-6 weeks. Third, with the digester
currently offline it is an ideal time to take care of these repairs.
Attached is a copy of the PO Request from Noelle Osborne, Plant Operations Supervisor,
Wastewater for a PO to be issued to in the amount of $43,571 and a copy of the quote
from Johnson Controls of Manchester, NH specifying the work to be completed.
Thank you,
cc: DPW Administration
229 Main Street » PO Box 2019 * Nashua, New Hampshire 03061-2019
603.589.3260 © fax 603.594.3450 * NashuaMayor@NashuaNH.gov
www.NashuaNH.gov
