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The City of Springfield’s sanitary sewer
collection system has its documented beginnings in 1894 when
the first sewers were constructed west of Grant between College
and Walnut streets. The system is now an extensive and growing
infrastructure that carries wastewater from area industries,
businesses, and residences to the wastewater treatment plants.
System Parameters
The sanitary sewer collection system provides service to 63,000
residential connections and 7,200 non-residential connections.
The sanitary sewer watershed area can currently be divided
into 15 drainage basins and 158 sub-basins. There are currently
27 lift stations. The system consists of over 1,000 miles
of gravity pipe, 28 miles of pressure pipe, and 23,000 manholes,
lamp holes, wet wells and flush tanks. The pipes vary in size
from 4 inches to 72 inches at depths of 3 feet to 94 feet.
New sewers are being built at a rate of 20-25 miles per year.
Materials
The initial sewers were built of brick and clay with
lime and cement mortar. The pipe materials evolved to cast
iron, concrete, reinforced and lined concrete, and polyvinyl
chloride (PVC). The pipe joint materials evolved from the
initial lime and cement mortar to jute, poured tar, polyurethane
gaskets, and neoprene O-rings.
Maintenance
The collection system is divided into three areas for cleaning
purposes. This division allows for quicker response and more
crew responsibility. A 2-man crew works in each area using
a high-pressure sewer jet/flusher or jet/vac with hydraulic
saws. An easement machine aids in rear property access. The
cleaning activities are performed on routine preventive and
accelerated preventive schedules based on maintenance history.
Each crew averages 2,700 feet of cleaning each 8-hour day.
On average there are 1,140 service requests from the public
and 154 stoppages occurring each year.
Repair
Two 2-man crews routinely perform sanitary sewer repair activities.
Additional staff is utilized as necessary. The crews operate
2 extenda-hoe backhoes and 4 dump trucks as needed. Each crew
completes over 100 repairs and replaces or rebuilds 10 manholes
per crew year. These same personnel also maintain the pressure
lines and air relief valves on the current 28 miles of pressure
pipe and perform snow removal duties on the streets of Springfield.
Infiltration and Inflow
A staff of 5 regular full-time and 15-20 contract employees
performs infiltration and inflow
reduction efforts. These personnel use several techniques
to locate and minimize extraneous flow into the sewer collection
system.
This section of the Sanitary Services Division has a total
of 25 regular full-time and 15-20 contract personnel.
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