American Water Pennsylvania – Ellwood WTP And RAW Water Facilities

Reynolds constructed a new 8 MGD (expandable to 16 MGD) water treatment plant and raw water intake facilities for Pennsylvania American Water’s service area in western Pennsylvania, at the confluence of the Beaver River and Connoquenessing Creek in New Beaver Borough and Wayne Township, Lawrence County, PA.

The facilities include:

• New 8 MGD raw water pump station (RWPS), expandable to 16 MGD on the west bank of the Beaver River. Water was pumped out of the clearwells to distribution by three 3500 GPM horizontal split-case centrifugal pumps.
• The raw water pump station was constructed above the shaft. 3’ thick reinforced concrete walls were poured vertically up the shaft.  Three vertical turbine pumps with 150’ columns were installed in pump cans connected to the raw water piping from the intakes.
• New 16 MGD capacity raw water intakes, one each located in the Beaver River and Connoquenessing Creek.
• Two sets of dual, 24-inch raw water intake mains extending from the diversion chamber to the intake screen configurations located in the Beaver River and the Connoquenessing Creek.
• Dual 24-inch raw water discharge mains extending from the RWPS to the limit of the WTP property.
• Design of an air burst intake screen system and a sodium permanganate chemical system housed in the RWPS and distributed to the intake locations in the Beaver River and Connoquenessing Creek.
• Permitting and approvals for intakes and temporary construction impacts with U.S. Army Corps of Engineers and PADEP. Developed a HEC-RAS hydrology/hydraulics model to predict stream bed/bank scour.
• 35’ diameter, 165’ deep shaft excavated through complex geology with groundwater control, for Raw Water Intake.
• 3-500’ microtunnels to dual river intakes, installed beneath sensitive waterways under PADEP and USACE permits.
• Open-Cut River Crossing executed under regulated seasonal conditions with sediment control measures.
• Two River Intakes
• Five coffer dams. 2 were in the river, and 3 of them were on land, supporting marine and trenchless works.

The plant provided for conventional treatment with inclined plate settlers and granular activated carbon gravity filters.  Chloramines were used for disinfection by-product control.  Ultraviolet disinfection was provided for U.S. EPA LT2 compliance, and the units are capable of operating in an advanced oxidation mode for treatment of taste and odor.

In addition to the water treatment area, we constructed a solids handling area which consisted of 2 – 60’ diameter clarifiers, 1 – 60’ diameter gravity thickener and a dewatering building.  Solids were processed by moving the settled solids out of the settling basins with a traveling sludge collector system into the gravity thickener.  The thickened sludge is pumped out of the thickener tank into centrifuges along with polymer, where it is dewatered into 20% solids sludge cake.  It is moved from the centrifuges with a spiral conveyor system, where it is dumped into containers and hauled off.  The clarifiers are used to process solids from the filter backwashing process.