City of Mason Water Reclamation Plant
Dried Sludge Silo
n 2006, The City of Mason began reThe Anaerobic (No-Oxygen) Zone, ﬁrst ceiving flow into a brand new Water stage, releases phosphorus from microorReclamation Plant, located on 36 acres ganisms. The second stage, the Low-Oxyat 3200 Mason Morrow Milgrove Rd. gen (Anoxic) Zone, is constantly recycling Since 2006 the City has made various im- ﬂow internally with the aerobic zone. provements and modiﬁcations to the plant, In the last stage, the High-Oxygen (Oxic and constantly works to operate this plant or Aerobic) Zone or Oxidation Ditches, as cost-effectively and efﬁciently as possible. phosphorus is taken up in greater quantity The City conveys raw wastewater than previously released. Two underwater through seven lift stations. This wastewa- aerators and the off gas from the dryer inter ﬂows into the plant through a 48-inch corporate air into the water to maintain sufdiameter trunk sewer into one of two wet ﬁcient levels of oxygen. Some of the mixed wells at the inﬂuent pumping station. With liquor in the oxidation ditches is continualthree (two 4,550 gpm and one 2,100 gpm) ly being removed. It is returned back to the submersible, centrifugal pumps in each wet anaerobic zone or sent off as wasted sludge well, the wastewater is pumped through a to the clariﬁers. Final clariﬁcation is performed by three 36-inch force main up to the screen and grit building and then ﬂows through treatment settling tanks aided by a positive suction by gravity. The inﬂuent pump station is ca- sludge withdrawal system. The inﬂuent is pable of pumping a peak ﬂow of 26 million pumped from under the tank up through gallons per day. a center inﬂuent feed well. The feed well is Preliminary treatment first passes equipped with bafﬂed scum ports that perthrough one of two ﬁve foot wide concrete mit ﬂoating material to escape from the top channels. Each channel contains a me- of the feed well to where it will be picked chanical perforated plate screen of stain- up by the scum rakes. Water is then used less steel panels with 6mm circular to carry it back to the head of the perforations that revolve on a plant for additional treatment. conveyor. The screens inMechanical Screens In addition, Ford-Hall Brushes are used in the clude mechanical brushtanks to help keep the es and a washing system to prevent clogging. edges and weir clear of After screening, the algal growth. wastewater enters one The effluent from of two 14-foot diamethe settling tanks ﬂows ter vortex grit removal through a ﬂow metered and classification units. ﬂume and past the Efﬂuent ﬂow from the grit medium pressure, collectors drops into a 48high intensity ulinch gravity pipe to the next traviolet system. step in the treatment process, To disinfect, the wastewathe oxidation ditches. ter ﬂows across The two oxidation ditches are Eimco A2C extended aerone of two banks ation, single stage nitriﬁcation, of UV light that is UV Channels biological nutrient removal (BNR) generated by rows of reactors with a capacity of 5.6mgd. long tubular bulbs. This process is streamlined for the removal The UV system automatiof phosphorus and nitrogen in three stages cally adjusts ﬂow pace to the intensity of which vary in the amount of oxygen avail- the bulbs according to the ﬂow leaving the able in the water. The levels of oxygen in the plant. It works similar to a dimmer switch in different zones support different actions by your home, but is done automatically. The speciﬁc types of bacteria used to treat the advantage of ﬂow pacing is the reduction in waste. power consumption which translates to a 28 CenterPoint Fall 2019
Sludge Dryer Front
cost savings on monthly utility bills. From disinfection, ﬂow is sent to different areas for ﬁnal distribution. The majority of the discharged water absorbs additional oxygen before entering a pipe that conveys it to the Muddy Creek. A portion of the efﬂuent is sent into an efﬂuent well that provides a reservoir for the reclaim water pumping stations that discharge to a local golf course for irrigation, a community sports park for irrigation and a non-potable water (NPW) system that serves the Water Reclamation Plant and provides cooling water to the bio-solids dryer and elutriation water pumps for the gravity thickener tank. By reusing treated water in the plant and at the park, the City saves thousands of dollars a year by not having to purchase treated drinking water for these purposes. The City of Mason’s Water Reclamation Plant construction has been a very successful investment for the City and its residential, commercial and industrial customers. For sewer emergencies between 7:00 a.m. and 3:30 p.m., Monday through Friday, call the City of Mason Public Utilities Department at 513.229.8570. Outside of these hours call the Warren County Communications Center’s non-emergency number at 513.925.2525. A call-out fee may be charged if the problem is not the fault of the City.