Page 20 - Sept/Oct 2018 Vol 36 No 3
P. 20
2017 CONFERENCE TECHNICAL SESSION EQ System from page 19 from one, two, or all three of the force staged operational scenario is in place.
mains to be rerouted to the EQ Basin by Each EQ Basin’s PLC includes logic
controllers (PLCs) were installed at each actuation of a series of motor operated
site with the capability to communicate valves. that determines at what point the EQ
status and alarms through the city’s Basin at that particular site can be drained
fiber optic system to the main PLC at EQ Basins back into the system. After a rainfall
the wastewater treatment plant, receive event has passed and the flow at the
commands from the main PLC, and The three EQ Basins were located at the junction begins to decrease, the control
control pumps and valves at the site. East Plant pump station, the confluence system automatically begins to empty
of the force mains from the East Plant the basins on a preset, staged basis. The
In conjunction with the EQ Basin pump station and the Emory Valley pump system is designed to empty the basins at
designs, three laser flow meters were station, and adjacent to the interceptor a controlled rate, based on the total flow
specified to be installed in manholes from the Scarboro Basin. being discharged to the main interceptor.
upstream of the junction to determine the
flow rate being discharged to the main The system at work Impact
interceptor. The flow meters, installed
at the three sites, collect flow data and Control of the overall system is The EQ system has assisted the City of
transmit real-time flow measurements accomplished by summing the flows Oak Ridge in meeting the requirements of
– via the fiber system – to the main PLC measured by the three laser flow meters the EPA mandate in a timely and effective
at the wastewater treatment plant. The and comparing the total to a preset manner.
East Plant and Scarboro EQ Basins were maximum allowable flow that can be
designed to operate independently based discharged to the main interceptor. Once Director of the City’s Department of
on flows at each site or remotely based on the total exceeds the preset maximum, Public Works, Shira McWaters, noted,
commands from the wastewater treatment the Emory Valley EQ Basin is put into “This project was one of many associated
plant PLC. The Emory Valley EQ Basin operation. with the City of Oak Ridge’s compliance
was designed to control the rate of flow mandate. It was a substantial undertaking
from two major pumping stations (East By utilizing instrumentation installed that showed the city’s commitment to
Plant and Emory Valley) by connecting at the basin sites and the flow meters addressing the mandate requirements,
the three force mains (one from East Plant installed in the three interceptors, instilling confidence in our program with
and two from Emory Valley) that passed transmitting the real-time data via fiber the regulators. Since construction, we
by the site into a manifold that allows flow to a dedicated PLC at the wastewater have seen the design come to fruition by
treatment plant, and developing logic to alleviating overflows and significantly
determine when and to what extent flows improving system operations.”
must be re-routed to the EQ Basins, a
20 TPW September/October 2018
