Date: Fri 05-Sep-1997

Publication: Bee

Author: ANDYG

Quick Words:

sewers-treatment-plant

Full Text:

with carryover cut: Town's New Sewage Treatment Plant Activated

B Y A NDREW G OROSKO

Wastewater cleansed at the town's new sewage treatment plant is now being

discharged into the Pootatuck River.

Workmen opened valves Tuesday diverting wastewater from Garner Correctional

Institution, Nunnawauk Meadows and the Fairfield Hills campus to the new plant

at the end of Commerce Road. The sewage from those facilities formerly was

treated at Fairfield Hills' old wastewater facility.

The sewage discharged from the more than 800 addresses in the town's sewer

district will drain to the new sewage plant for processing.

The almost $9-million plant built by CH Nickerson and Company of Torrington

has a treatment capacity of almost one million gallons per day. Two-thirds of

that amount is reserved for the state, with the remainder designated for town

use.

The plant is surrounded by a security fence intended to keep people away from

large, deep sewage oxidation ditches and clarification tanks used in the

treatment process, plus various electrical and plumbing equipment.

Town and state officials plus engineering staff celebrated the opening of the

sewage treatment plant Wednesday at a ribbon-cutting ceremony in front of the

administration building.

"This is state-of-the art," explained George Vercelli, the engineer who

designed the facility. Mr Vercelli is an associate/senior project manager for

Fuss and O'Neill, Inc, the town's consulting engineer. Newtown's plant is one

of the most advanced wastewater treatment facilities in Connecticut, Mr

Vercelli said.

To eliminate the need for chlorinating sewage, the plant was designed with

arrays of underwater ultraviolet light banks for disinfection purposes, he

said. Chlorine is a toxic substance which can pose safety hazards.

The sewage plant includes "denitrification" equipment intended to reduce

wastewater nitrogen levels, with the long-range goal of limiting the amount of

nitrates that travel from the Pootatuck River into the Housatonic River and

eventually Long Island Sound.

After reaching the treatment facility from different directions, sewage passes

through an "explosion-proof" headworks building. The building is designed to

withstand an explosion if there is a buildup of methane gas. Large objects

which find their way into the sewer system will be trapped in the headworks

building for removal.

After leaving the headworks, the effluent flows into oxidation ditches,

clarification tanks and a filter building. Chemicals are added, as needed, to

regulate the acidity/alkalinity balance of the water, said Fred Hurley,

director of public works. Wastewater is forced through sand filters in the

filter building to cleanse it.

The treatment plant is designed with redundant features throughout to ensure

its reliability, he said. A 500,000-watt generator is positioned near the

filter building to run the plant in the event of power outages.

The administration building contains a sophisticated chemistry laboratory

where samples are tested. Overall control of the plant and four sewage pumping

stations is regulated there on a networked computer running software

customized for the Newtown plant.

If no one is at the plant and an emergency crops up, an autodialer places

telephone calls to plant operators and plays a recorded message describing the

problem. Linking remote-based laptop computers to the control center via

telephone lines allows off-site operators to further diagnose problems,

learning whether an immediate trip to the plant is necessary to correct

problems.

After wastewater has been processed, it exits a culvert and enters a

meandering rock-lined trough where the town has planted a variety of trees and

shrubs to create a natural setting.

The trough discharges water into the Pootatuck River which is stocked with

trout by the state.