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By Charles E. Herdendorf
The Village Pioneer, 12-09, Volume 4 Number 4, page 8
Just south of the Abbe Road bridge over French Creek, an attractive sign announces the entrance to the French Creek Water Pollution Control Plant. The plant treats wastewater from the communities of Avon, North Ridgeville, and Sheffield Village.
A long, tree-lined drive leads to the 37-acre facility, better known as the French Creek Wastewater Treatment Plant, operated by the City of North Ridgeville. In late October the sycamore trees that line the drive were in full fall color as a contingent from the Sheffield Village Historical Society approached the gate and announced our presence to a communication box. The electronic gate slowly opened and we were advised to come to the Administration Building and sign in.
Soon we were joined by Plant Superintendent Donald D. Daley, who graciously answered our many questions and personally guided us on a 2-hour tour of the facility. Having been in charge of the plant for 22 years, it was obvious that Don Daley was proud of the French Creek Wastewater Treatment Plant, and we all agreed after our visit that his pride was well justified.
Plant History
Taylor "Jack" Smith of the Avon Historical Society has explored the history of the French Creek Wastewater Treatment Plant. Jack traced the plant's establishment back to 1966 when the Ohio Water Pollution Control Board urged the communities of Avon, North Ridgeville, and Sheffield Village to form the French Creek Sewer District. Avon resisted the idea, calling the plan a "marble outhouse." In response to Avon's lack of support for a sewer district, in 1968 the State imposed a building freeze on Avon.
Avon citizens repeatedly voted against sewers, believing the building freeze would stop growth and preserve green space. In 1971, the Ohio General Assembly passed a bill giving the Ohio Water Pollution Control Board the power to direct the Ohio Water Development Authority (OWDA) to build sewage treatment facilities and levy assessments upon users to pay for construction costs. After a long period of negotiation, in November 1973 the Councils of Avon, North Ridgeville, and Sheffield Village approved a final contract with the State of Ohio to build the treatment plant.
Leo Sheets was serving as Sheffield Village Administrator during the original construction of the plant. Leo recalls that Johnson & Anderson Engineering of Pontiac, Michigan performed the engineering design and construction inspection for the plant.
The deep trench [along French Creek] required for the 54-inch main interceptor pipeline was hand-dug by coal miners from southern Ohio and West Virginia. Crossing Abbe Road at several locations, at times 20 feet of shale bedrock had to be excavated along the route through Avon and North Ridgeville. With construction of the plant underway, the State lifted the residential building ban on Avon, but kept the commercial/industrial restriction in place until the plant was opened.
The $23 million plant was completed in 1975 by the Ohio Water Development Authority, under Director Ned Williams, P.E., being funded by the federal (75%) and state (25%) grants, with only a minor contribution from the local communities.
For several years the Ohio Water Development Authority operated the plant. Although the plant was designed to process up to 7.5 million gallons of wastewater per day (mgd) in the early years it only handled about 1.9 mgd. In 1983, the State offered to sell the plants to the local governments. Avon and Sheffield declined the offer.
Under Mayor Dick Noll, North Ridgeville's offer of a mere $11,000 was accepted. For this reason, the City of North Ridgeville now operates the wastewater treatment plant in the heart of Sheffield. But that's all water over the dam, or should I say wastewater down the sewer -- now we can be proud that one of the most modern and efficient treatment plants in the region is located in our community.
Service Area
The French Creek Wastewater Treatment Plant services the French Creek Sewer District, which encompasses the entire communities of Avon, North Ridgeville, and Sheffield Village, an area of nearly 50 square miles. In terms of wastewater processed by the plant, the breakdown is as follows:
North Ridgeville 60%
Avon 30%
Sheffield Village 10%
At slightly over 10 square miles, Sheffield Village is only about half the size of the other communities, but the other reason for the low percentage is that only the neighborhoods along Abbe Road have sewer lines; the remainder of the Village relies on septic tanks for wastewater disposal.
The annual budget for operating the French Creek Wastewater Treatment Plant is $5 million, contributed by the three participating communities at the approximate percentage listed above for the wastewater delivered to the plant for each community.
The budget, rate charge, and other major operating/improvement decisions are made by the City of North Ridgeville on the recommendations of the plant management in consultation with a Satellite Sewer Committee, composed of representatives from the participating communities.
Sheffield's representatives on the Committee include Mayor John Hunter and Village Administrator Ken Kaczey. The communities in turn, set and collect user fees from residents and businesses as needed to meet their individual budget responsibility.
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Infiltration
Don Daley explained a problem that occurs throughout the service area -- a phenomenon know as "infiltration." Surprisingly, about 30% of the wastewater that enters the plant does not come from sewer drains; it comes from groundwater.
When the water table is high, groundwater seeps into breaks in the lateral sewer pipes. The older lines, particularly in Avon and North Ridgeville, were constructed with vitrified (glasslike) clay pipe that often breaks when the ground settles. With some 100 miles of pipe, the amount of groundwater infiltrating through these breaks can be significant.
On average, about 2% of the sewer lines need to be replaced annually in a well-maintained system. Fortunately, Sheffield's sewer lines are much newer and were constructed with reinforced concrete pipe that is much less prone to breakage.
During dry periods, when the water table falls below the sewer pipes, the reverse process can occur as wastewater leaks out and can contaminate the groundwater. Drinking water lines are also prone to similar failures. Typically about 19% of the water carried by potable water lines is also lost through leaks in the system.
How the Plant Operates
The French Creek Wastewater Treatment Plant has 23 full-time employees. Typically the plant operates 16 hours a day, in two shifts, and then is idle for 8 hours.
The plant processes from 5.8 to 7.2 million gallons of wastewater each day. All of the sewage-laden water enters the treatment plant by gravity flow. To accomplish this, the 54-inch diameter main interceptor pipe is set 75 feet below the ground surface, four floors below the Administration Building.
Here, a series of five huge pumps, each capable of pumping 3,750 gallons/minute, convey the inflowing wastewater to a large Wet Well some 25 feet above the ground. From the well the wastewater begins a 12-hour journey through the treatment plant.
At the end of the process two things remain: purified water that is discharged to French Creek just upstream of the Norfolk & Southern Railroad bridge, and inert sludge that has been processed for beneficial uses.
The first stage in processing the wastewater consists of collecting large pieces of solid debris on bar screens located just ahead of the pumps under the Administration Building. From the Wet Well raw sewage flows by gravity to the Grit Building, where sand- to fine gravel-sized particles and solids of high specific gravity settle at the bottom of a Grit Tank.
Some of the items collected on the screens are bizarre, including false teeth, hypodermic needles, diamond rings, wallets, and cash (one roll had $150 dollars of soggy bills).
From the Grit Building the wastewater again flows by gravity to a Mixing Well and then to one of three Primary Clarifiers, circular digestion/settling tanks 120 feet in diameter, which consist of an outer ring where agitation occurs, and an inner ring with a revolving center shaft at the bottom fitted with plow-like blades that push the deposited sludge toward a central discharge hopper.
In the outer ring, aeration tends to break the sewage into fine particles and it aids in the biological digestion of organic waste materials.
The microbial community bringing about the degradation of organic wastes, known as the Activated Sludge Process, is maintained in suspension in the liquid by diffused air. The wastewater in the clarifier literally appears to boil from the air injected into the tank from large compressors.
Wastewater is continually recycled back to the Mixing Well where it mixes with incoming raw sewage for a period of 4 to 6 hours. The plant operator monitors the microbial content of the liquid in the Clarifiers.
When the bacterial count reaches the proper "sledge age" of 2,500 to 3,500 milligrams per liter (mg/l) of mix liquor suspended solids (MLSS), the wastewater is ready for the next step. The particular two-ring design at the French Creek Wastewater Treatment Plant, in conjunction with recycling the wastewater, is referred to as the "Walker Process."
The next step in the process, Filtration, consists passing the water from the Clarifiers through sand or membrane filters. The preferred filter at the plant is a 3-ft square woven-cloth membrane that looks and feels much like the inside of a fleece-lined jacket. A series of six membranes, mounted on steel frames, are set into a sluiceway where the filtration occurs. The membranes are capable of being back-flushed to clear out the filtered particles and are relatively durable, lasting up to five years.
The final step in the process involves passage of processed wastewater down a 251-ft-long concrete channel where final sedimentation of any particulate matter occurs. The channel was originally designed as a chlorine gallery where chemical disinfection was once used.
Since that time chlorine-based compounds have been found to be deleterious to the ecology of streams. Now, at the end of the channel ultra-violet rays are pasted through the water. Working much like microwaves, they disinfect the processed water before it is discharged into French Creek. This step in the process is known as "polishing."
Sludge from the various collections points within the plant is carried to the Sludge Building for final processing. Here, powerful centrifuges further dewater the sludge through a recycling process.
This digested sludge is only about one third of its original volume and is a rather inoffensive, humus-like material. From the Sludge Building the final product is carried by a conveyor system to an exterior storage yard on the southwest corner of the site. Currently classified as Class B sludge, plans are underway to provide internal storage and upgrade the material to Class A.
Flooding Out
Rainstorm infiltration is one of the most serious problems for the treatment plant. The plant can cope with up to twice the normal rate of wastewater during a storm, but when rainfall exceeds 2 inches the plant is prone to flooding.
In the early years of plant operation, the amount of wastewater during heavy storms exceeded the plant's capacity to process it and the plant was flooded out on several occasions. With the approval of the Ohio Environmental Protection Agency, large holding tanks (1.5 million gallon-capacity) were constructed near the plant's outfall pipe to temporarily hold excess raw sewage and blend it with processed wastewater before releasing it to French Creek. This bypass situation typically occurs once or twice each year.
Severe cases of flooding took place in 1976 were sewer manhole covers were inadvertently left open in North Ridgeville during a rainstorm and on August 20, 2005, when an estimated 5.8 inches of rain fell on the French Creek watershed, a near 100-year storm event.
Other features of the plant include 1.2 miles of lighted tunnels to carry utility lines. The tunnels originate in the second floor of the Administration Building and are large enough for two people to walk abreast. During the winter some of the plant's staff keep fit by running the tunnels.
An impressive electrical room is located nearby, where incoming electromotive force of 69,000 volts is ultimately stepped down to 220 and 110 volts. A modern water quality laboratory is located in the Administration Building, where testing for hazardous/toxic chemicals and pathogenic bacterial is routinely conducted. The main control center is also located in this building. Here, computerized graphic displays of the various components of the plant permits an operator to monitor all aspects of plant operation.
Plant Innovations
Don Daley and his Assistant Superintendent Mark Francis are continually looking for ways to make the plant more efficient and develop services that bring additional revenue to the plant. In recent years the plant has been fully automated with computer technology. Don Daley noted, "In an emergency, I could operate the plant from home on my laptop.
"Under Don's leadership, the plant has undergone a major expansion. HB Engineering of Middleburg Heights was selected as the prime contractor to engineer the project, which increased the wastewater capacity of 7.5 mgd to 11.25 million gallon per day. Completed in 2003, the expansion was paid for by user fees, tap-in fees, and charges to septic haulers.
One of Don's main goals is to avoid crisis management through forward thinking to anticipate and be prepared for to deal with unexpected situations. To accomplish this Don has instituted a program of "cross-training," whereby employees are given the opportunity to learn the how to do the jobs of other staff members if the needed arises.
One of the newest innovations at the plant is Industrial Pre-Treatment (IPT). From area industries, several tank trucks arrive daily carrying non-toxic wastes too chemically enriched to be flushed directly into the sewer system. At the IPT building these wastes are processed under strict State regulations and rendered safe for regular treatment in the main plant.
Some of the industrial waste contains high levels of phosphate, an unwanted nutrient that stimulates algal growth in streams and Lake Erie. The IPT facility removes the phosphate by treatment with ferrous chloride (FeCl3), before the industrial wastewater is directed to the regular treatment process.
Under the direction IPT foreman Lou Cover, this new process earns from $25,000 to $38,000 a week in fees from user industries. The proximity of this new treatment option to Sheffield's business and industrial properties should place the Village in an advantageous position to attract new industry.
Another source of funds to offset some of the operating cost for the plant comes from fee charged to septic haulers. Across northern Lorain County some 19 companies, in business to pump out septic tanks in unsewered regions of the County, bring their sewage to the French Creek Wastewater Treatment Plant for processing. Last year (2008), fees paid by the septic haulers amounted to $489,000.
Sludge is an important by-product at the treatment plant where 20,000 tons (about 60,000 cubic yards) of material is produced annually. The sludge is suitable for many practical applications, such as garden mulch and soil conditioners. Large quantities of sludge from the plant are trucked to Huron County for agricultural purposes. Working with Ohio State University Professor Terry Logan, Don Daley has developed a liquid sludge product that has been applied to farm field near Castalia, Ohio.
Within the next several months a large building will be constructed at the west end of the facility site for storage sludge. Approval of this material as Class A (best classification for multiple uses) is now pending approval from the Ohio EPA. The building will also house a sludge bagging apparatus.
This spring the plant plans to have 40-lb, bright yellow bags of sludge available free of charge to citizens of the participating communities. Probably the most intriguing use of sludge is currently being worked on by Dr. Logan and Don Daley -- Green Fuel.
Well, maybe not really green in the color sense -- more of an earthy brown! The concept is to pelletize the sludge to form an environmentally friendly fuel for electric power generating plants and commercial landscape nurseries. Pellitized sledge has been shown to ignite at 500°F, which makes it an ideal alternative fuel for local power plants that now burn sulfur-laden coal or in the case of nurseries that burn corn.
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