16 CONNECTICUT GREEN GUIDE • FALL 2016 www.CTGreenGuide.com
Manchester's $51M
plant overhaul
means cleaner river
L
ike its wastewater compatriot 37 miles down the
highway in Cheshire, a $51 million overhaul of
Manchester's wastewater treatment plant was
also spurred in part by aging equipment and stricter en-
vironmental regulations meant to protect the health of
rivers that ultimately flow into the Long Island Sound.
Construction at the Hockanum River Water Pollution
Control Facility (WPCF) began in 2011 and wrapped up
in mid-2015.
The liquid discharged from WPCF into the river is the
cleanest it has ever been. The plant, which is expected
to meet Manchester's needs for the next two decades, is
well below the discharge limits for nitrogen and phos-
phorous imposed on it by the Department of Energy
and Environmental Protection.
Excess levels of nitrogen and phosphorous in marine
habitats fuel the growth of algae, which ultimately
reduces the amount of oxygen available for plants and
fish, a condition known as hypoxia.
The new plant removes 94 percent of the nitrogen
present within the 6.5 million gallons of sewage it
takes in each day. That's up from 30 percent or less
pre-construction. The difference is as large as 900
pounds per day being discharged to the river.
WPCF also now removes 95 percent of phosphorous;
previously it removed virtually none. The plant emits
approximately four pounds of phosphorous each day,
well under its regulatory cap of 13.4 pounds. It does so
using a "ballasted flocculation" system, which employs
clam and oyster shells as filters in a process that also
breaks down odors from waste.
Like Cheshire, Manchester's plant also received
incentives from Eversource to acquire more energy-
efficient equipment.
Manchester Sewer Department
PROJECT ELEMENTS: Facility-wide; water; material
management; innovation
START DATE: DEC. 2011
COMPLETION DATE:
July, 2015
Manchester's
new water
treatment plant
has dramatically
reduced chemical
discharge into the
nearby Hockanum
River.
PHOTO | MIKE EMOND
CATEGORY: Government
GreenCircle Sustainability Awards 2016
