PT Building Upgrade Design
Funded through New Jersey Environmental Infrastructure Financing Program
Funding Project No. S340821-05
The NJDEP based on Level Environmental Review has made a decision to approve the planning information for the proposed action. This decision is a part of the financial application process, but is not a commitment of federal or state funds. An environmental summary of the proposed action, including the basis for determining that it qualifies for a Level 1 Environmental Review, is enclosed.
The Rockaway Valley Regional Sewerage Authority (RVRSA) wastewater treatment plant is located in Parsippany-Troy Hills, Morris County, and its upstream Siphon Screening Chamber is located in the Town Boonton. The plant was originally constructed in the early 1920’s. Upgrades to the plant current capacity to 12 million gallons per day (MGD) went on-line in September 1985.
Under Contract X, these upgrades included installation of a four barrel siphon under the Rockaway River, and construction of Preliminary Treatment Building (PT Building) and Secondary Treatment Facilities.
The four barrel siphon extends a total of 2,167 feet in length. The section crossing the Rockaway River is 353 feet in length and consists of four horizontal concrete encased 24” ductile iron pipe (DIP) barrels, of which, three are active and one has plugged stubs on both ends. From the river crossing, three 24” DIPs continue 306 feet south to the Distribution Box at the head of the Preliminary Treatment Facilities which are located approximately 700 feet south of the Secondary Treatment Facilities. From the 17-foot wide Siphon Cleanout Chamber located at the river crossing, three 24” DIPs continue 1,491 feet north to the face of the Siphon Screening Chamber.
The concrete Siphon Screening Chamber located between the interceptor and the siphon lines has been subject to hydrogen sulfide (H2S) deterioration and requires rehabilitation.
The Preliminary Treatment Facilities consist of the Distribution Box (located just west of the PT Building), influent pipes, and the PT Building which houses influent channels, screening facilities, slide gates, and grit removal equipment. The Distribution Box directs flow from the siphon to the PT Building through four influent pipes. Each influent pipe discharges into an influent channel containing screening equipment. Two channels have mechanically cleaned bar screens and two channels contain manually cleaned bar screens. The screenings removed from the mechanical bar screens are discharged into a compactor which discharges the compacted screenings onto a screw conveyor which conveys the screenings into a bag.
The screenings channels discharge into a common channel from which flow enters the aerated grit chambers. There are four aerated grit chambers, only three of which are operable and contain equipment. The aerated grit equipment consists of a motorized chain which operates the screw collector in the bottom of the chamber. The screw collector moves the grit to a sump from which buckets on the chain remove and convey the grit to a grit classifier. The classifier cleans and discharges the grit onto a grit conveyor which transports the grit to a hopper.
Modifications were made to the original PT Building which included removal of the comminutors with the current Schloss mechanical bar screens. Since then, failure of the HVAC system, and elevated H2S concentrations have led to the corrosion of piping and exposed steel within the building. The mechanical bar screens have reached the end of their useful life and undergo frequent repairs. The chain drives in the aerated grit chambers frequently break and lead to the accumulation of grit in the grit chambers which need to be removed by vacuum equipment.
The existing condition of the preliminary treatment facilities has led to accumulation of screenings and grit throughout the secondary treatment facilities, as well as within the Distribution Box and PT Building. The H2S concentrations within the PT Building have resulted in deterioration of equipment, exposed metal and piping, and create difficult working conditions.
RVRSA proposes to make modifications to the PT Building facilities under Contract 36, which will be funded by this NJEIT loan. The work to be included in this contract consists of the following:
a. Siphon Screening Chamber
Remove all loose concrete, repair interior walls and ceilings, and coat with an epoxy surface which will protect the concrete against H2S concentrations.
Install an odor treatment system at the siphon screening chamber to treat the H2S concentrations.
b. Distribution Box
Install motorized operators on the two main influent sluice gates at the Distribution Box to facilitate cleaning of grit accumulations in the Distribution Box.
Replace the existing aluminum grating at the Distribution Box with fiberglass plates to contain H2S odors within the Distribution Box. Piping will convey the area under the plates to a proposed odor treatment system located within the PT Building.
c. PT Building
Replace all existing aluminum grating over the channels with fiberglass plates.
Install an odor treatment system which will remove the air from the Distribution Box, under the channels and from the aerated grit chambers and treat the H2S before discharging the air.
Replace the existing grit removal systems in the three aerated grit chambers with new chain-driven systems.
Replace the two existing mechanical bar screens with new mechanical bar screens. The new screens will discharge into new washer compactors which will discharge into bags.
Install a new HVAC system for the building.
Install a new roof on the PT Building.
Install an aluminum stair on the exterior of the PT Building to provide access to equipment on the roof.
Replace the existing sluice gates within all four aerated grit chambers.
Provide motorized operators on two influent channel sluice gates.
Modify existing slide gates replacing plates and stems.
Replace the existing City Water, and service water hose bib assemblies.
Replace the existing roof drain piping.
Replace all gas detection and O2 monitoring instrumentation.
Clean and paint all exposed steel.
Remove existing 5-ton hoist, and replace existing 1-ton hoist.
Clean the existing tile walls and remove the existing rest room.
Replace existing aluminum doors with new fiberglass access doors.
Replace the existing temporary truck dewatering pad located outside the PT Building with a new permanent structure.