J-1606000-03-02 WTP AND DISTRIBUTION SYSTEM DESCRIPTION 2.docx

ATTACHMENT J-1606000-03-02

WATER TREATMENT PLANT AND DISTRIBUTION SYSTEM DESCRIPTION

The Contractor shall develop, submit and implement an Integrated Maintenance Program (IMP) for the water systems and all mechanically and electrically interlocked ancillary parts, equipment, and components of the system including but not limited to wells, raw water piping, manual and automatically operated valves, hangers, fittings, vents, blow offs, check valves, pressure gauges, pressure sensors, variable frequency drives (VFDs), radio transmitters, control panels, monitoring gauges and meters, chemicals, water heaters, mixers, injectors, gaseous chlorine feed system and components, lime silo and fill and feed system and components, Wisprofloc polymer storage, mixing and feeding system and components, booster pumps, back flow preventers, fluoride storage, mixing and feed system, air compressors, air dryers, air filters, compressed air systems and components, fluid level and flow control systems and components, lift stations, screens, strainers, splitter boxes, centrifuges, conveyers, augers, water pumps, water/sludge separating equipment and additional equipment and components that perform the process of lifting raw water from the underground aquifer and creating finished water.

The existing Naval Support Activity Annapolis (NSAA) Water Treatment Plant (WTP) supplies an average of 0.98 million gallons of water each day to The United States Naval Academy (USNA). It obtains raw water from three groundwater wells and treats groundwater with a relatively high concentration of dissolved iron. The plant design capacity is 2.3 MGD, based on a clarifier design capacity limitation of 800 GPM/unit. The WTP operators monitor the plant and system twenty-four (24) hours per day, seven (7) days per week. When ground storage tanks are measured at low levels, the operators command the well-pumps to operate. Raw water is pumped from one or more of three supply wells to tray aerators on the roof of the WTP building. Following aeration, gaseous chlorine, dehydrated lime, Wisprofloc polymer and fluoride are injected ahead of the two solids contact clarifiers. Settled water is filtered via seven DynaSand® continuous backwashing, up-flow, deep bed, mono-media sand filters. Iron sludge from the two coagulation (COAG) tanks is drained out at the discretion of the operators. The iron sludge flows to the two gravity thickener tanks and then the sludge is pumped to the two centrifuges. The iron sludge is dewatered by the centrifuges; the iron cake is dropped into a dumpster to be hauled off NSAA property and disposed of appropriately by the Contractor. The centrate water is recycled back to the head works of the plant.

The process water that has passed through the DynaSand filters receives a final dose of gaseous chlorine and then considered finished water. The finished water flows down from the filter room to two (2) one-million-gallon ground storage tanks. The GST levels are constantly monitored by the operators. At the time that operators observe the Elevated Storage Tank at low level and needing to be filled, the operators turn on one of the four high lift pumps and fill the EST. The level of water in the EST controls the pressure of the water in the entire distribution system. The operators continuously monitor the Finished Water Flow Meter to understand the current water demand of the Yard. The Operators must maintain daily operating reports per MDE Permit. Once the finished water flows out of the plant through the finished water flow meter, it enters the distribution system. The distribution system is made up of piping material that includes ductile iron, cast iron, PVC, copper, and range in size of 1 inch to 14 inch. The system is arranged such that there is 100 percent uni-directional flow to all facilities. Water distro piping is located underground, in utility tunnels, and above ground. The distro system includes all fire hydrants, valves, fittings, and other necessary components to ensure leak free delivery of finished water to all facilities. Services like uni-directional flow flushing, 100 percent valve exercising, and fire hydrant preventative maintenance program ensure the proper function of the distribution system.

The North Side NSA water distro system is supplied with water from Anne Arundel Co at the intersection of Kinkaid Rd and Greenbury Point Rd. The potable water flows through the twelve (12) inch back flow preventer to the AA Co meter. Once the water is through the meter it flows to the twelve (12) inch electronic open/closed tower level control valve. The control valve is commanded open and closed according to the pressure at the base of the water tower USNA-130RL. The water distro system is 100 percent uni-directional flow. The distro system is constructed of ductile, cast iron, PVC, copper and brass and ranges in size from 1 inch to 12 inch. The Contractor is responsible to perform uni-directional flow preventative maintenance, 100 percent valve exercising, and fire hydrant preventative maintenance annually to ensure the water distro system is in proper working condition. The average annual flow of potable water in the North Severn water system is 93,000 KGAL. Annapolis Partners (Formerly David Taylor) is supplied potable water from the Navy distribution system. There are six locations where the Navy potable system enters AP property. Only one twelve (12) inch, metered water supply line is contracted to be provided to Annapolis Partners (AP). The one twelve (12) inch metered water line that feeds AP is on Kinkaid Rd. The other five water lines are secured from Navy distribution system into AP property.

Informational Note: Attachment J-1606000-04, Water Utilities Overview Document, is provided for informational purposes only. It is purely supplemental and diagrammatical in nature. It is not necessarily an accurate representation of current system configuration but can help with understanding the overall system.