Huntington Wastewater Treatment Plant

Areas Served: City of Huntington, Spring Valley Public Service District, Monel Park Public Service District, Northern Wayne Public Service District.

Location: Westmoreland Section of the City of Huntington.

Total Occupied Land Area: Seven (7) acres

Project costs:

Primary Facilities Completed in 1964: $8,500,000.00
( Local Funds: $7,000,000.00 - Federal Funds: $1,500,000.00)

Secondary Facilities Completed in 1984: $21,765,792.00
(Local Funds: $5,141,448.00 - EPA Funds: $16,324,344.00 - State Funds: $300,000.00)

Sludge Dewatering and Incineration Facilities: $9,258,649.00
(Local Funds: $214,259.00 - EPA Funds: $6,943,970.00)

Coal Handling Facilities: $1,256,959.00
(Local Funds: $314,259.00 - EPA Funds: $942,700.00)

Total Design Capacity: 17 million gallons per day

Present Daily Average Flow: 13 million gallons per day

Total Sludge Disposal Capacity: 26,000 tons per day

Total Tank Volume: 2,244,000 cubic feet

Total Connected Motor Horsepower: 3,840 Horsepower

Operation and Managerial Responsibilities

Proper operation and maintenance is vital if the Huntington Wastewater Treatment Plant is to consistently meet the performance requirements imposed on it by law. The primary purpose of the facilities is to control water pollution discharges and protect our natural water resources.

Description of Treatment Facilities

The raw sewage at the Huntington Wastewater Treatment Plant arrives through a 54 in. force main. The wastewater first passes through a flowmeter vault which continuously measures the flow entering the plant.

From here the wastewater is sent into screening channels equipped with a dual bar screen system. The mechanical bar screens remove large debris which can damage pumps and other treatment processes downstream.

The wastewater now enters a combination preaeration and grit removal tank in order to freshen the waste flow and remove the grit. Air is supplied to the tank by air blowers. A screw conveyor transports the grit to a truck for disposal at the landfill.

The flow then passes through the primary clarifier tanks whereby the heavier solids settle out and are removed from the bottom of the tank and the floating solids (scum) are drawn off the water surface.

In the secondary process, the sewage flow passes through a battery of eight aeration tanks which provide means to keep the contents in an oxygen-rich environment by adding air directly into the tanks by way of air blowers. After aeration, the flow passes through the eight final settling tanks. As in primary settling, the settled solids are drawn off the bottom and scum drawn off the top of the water surface.

The flow which passes through the final clarifiers goes through the two chlorine contact tanks where disinfection takes place by adding dissolved chlorine gas to the flow.

The waste sludge which is not returned to the aeration tanks to effect the basis for the activated sludge process is thickened.

The concentrated solids which are drawn off of the solids thickeners are pumped to sludge holding wells. From here, the sludge is pumped to the ultimate disposal processes.

Agencies Having Jurisdiction

The responsibility of protecting the water resources within the state is vested in the West Virginia Department of Environmental Protection (WVDEP). In addition, the US Environmental Protection Agency (EPA) has the responsibility of preserving the quality of the nation's waters. These Agencies are required by law to enact and enforce rules and regulations which limit the quantity and quality of wastewater discharges. Under the provisions of the State of West Virginia, the Federal Water Pollution Control Act Amendments of 1972 (PL 92-500), and the Federal Clean Water Act of 1977 (PL 95-217), all wastewater discharges within the state are required to obtain permits from these agencies.

The Huntington Wastewater Treatment Plant is operating under state and federal discharge permits which require the facility to comply with both specific provisions contained in the permits as well as other rules and regulations which are applicable. Failure to comply with the permit provisions and applicable EPA and (WVDEP) rules and regulations is a violation which may result in the imposition of civil and/or criminal penalties including fines and/or imprisonment.

Discharge Permits

National Pollution Discharge Elimination System Permit (NPDES)

Under the provisions of the Federal Water Pollution Control Act Amendments of 1972, the EPA established the National Pollutant Discharge Elimination System (NPDES) permit program. The NPDES program requires all wastewater dischargers to apply and obtain a discharge permit. In conformance with this program, the Huntington wastewater Treatment Plant was issued NPDES Permit Number WV 0023159 by the administering state agency, the West Virginia Department of Environmental Protection (WVDEP).

The NPDES Permit sets forth both the volume and characteristics of the wastewater which may be discharged. Section 1 of the Permit sets effluent limitations for both the concentration of pollutants contained in the discharge and also the quantity (pounds) of the particular pollutant which may be discharged.

Description, Operation, and Control of Wastewater Treatment Facilities

General
Regardless of how well the wastewater facilities are designed, the care with which they were constructed, or the quality of the equipment utilized, the facilities cannot achieve their intended purpose unless properly operated. Efficient operation cannot be achieved without a clear understanding of the functions each unit is intended to perform and the basic engineering principles utilized.

Design Criteria
The criteria utilized for the design of the Huntington Wastewater Treatment Plant appears in Exhibit E. This table presents the basic parameters for which the facility was designed to handle. These parameters are vitally important to the operator in assessing the performance of the facilities and in establishing certain process control relationships.

Treatment Capacity
The design criteria for the facility are based on the projected service population in the year 1985 of about 96,633. The main treatment plant processes are designed to handle an average daily flow of 17 mgd and a maximum design flow of 46 mgd.

The facilities are designed to handle an average daily organic loading of 28,900 pounds of BOD5 per day and an average solids loading of 20,000 pounds per day. At the design average loading conditions, the facility is capable of removing 85 percent of the organic loading. The final effluent should contain less than 30 mg/L BOD5 and less than 30 mg/L suspended solids for the daily average.

Pretreatment Facilities

General
Pretreatment facilities are provided to condition the raw sewage coming into the treatment plant in such a manner that it is more suitable for the subsequent treatment processes. The purpose of pretreatment is to remove or neutralize constituents in the raw sewage which could clog or damage equipment or adversely affect the sequence treatment process.

Pretreatment facilities are generally designed to:

1. Remove or reduce the size of organic solids such as pieces of wood, paper, rags, or plastic.
2. Remove heavy inorganic solids, referred to as grit, such as gravel, sand, and cinders.
3. Meter the amount of flow entering the main treatment processes.

Primary Treatment

General
Huntington Wastewater Treatment Plant uses four rectangular sedimentation basins for primary treatment. The tanks are equipped with sludge and scum collection devices which will be discussed in detail in this chapter.

Process Description
The primary treatment facilities serve to reduce the organic loadings applied to the secondary treatment units. The operating costs of secondary treatment facilities is directly proportional to the organic loadings applied to them.

This primary treatment facility utilizes plain sedimentation to remove the heavier organic solids from the wastes. The removal of these solids will reduce the BOD content of the waste from 30 to 40 percent. The remaining BOD in the waste is either contained in solids which are too small and light to be removed by plain sedimentation or are in the dissolved form. Biological or chemical processes must be resorted to in order to further reduce the BOD content and remove the solids remaining after plain sedimentation. Activated sludge is the secondary process used to further treat the wastewater.

Secondary Treatment

General
Huntington Wastewater Treatment Plant uses activated sludge as its secondary treatment process. The activated sludge process consists of eight aeration tanks and eight final clarifiers with the capability of different modes of operation.

Process Description
Activated sludge is the biological process utilized to reduce the pollutants in the wastes to within the limits mandated by the permits. This is the secondary treatment process following primary treatment at the Huntington Wastewater Treatment Plant.

The activated sludge process consists of essentially two steps. In the first step, the influent wastewater is brought into contact with a performed biological floc, termed “activated sludge.” This is then followed by the liquid-solids separation step, whereby the biological solids are separated from the treated wastewater in a sedimentation tank and returned to be mixed again in the aeration tank as needed.

The activated sludge consists of billions of micro-organisms. When mixed eith the raw wastewater, these micro-organisms absorb and oxidize the carbonaceous organic matter in the raw sewage as a food source and produces more micro-organisms. The newly formed micro-organisms continue to grow in the aeration tank and clump together or flocculate to form activated masses of micro-organisms or biological floc. Air is introduced into the aeration basins to thoroughly mix the activated sludge with the raw wastewater and to supply the oxygen needed by the aerobic micro-organisms to break down the organic matter.

The mixed liquor flows from the aeration tanks to the sedimentation tank where the biological floc or activated sludge can be settled out by gravity. Because the biomass or sludge continues to be produced as more organic matter is removed from the wastewater and new micro-organisms are formed, more sludge is produced than can be used by the process. Therefore, it is necessary to remove some of the excess return activated sludge from the system. This waste activated sludge is diverted or “wasted” to the sludge handling facilities for treatment and disposal.

Disinfection Process

General
The primary purpose of the wastewater chlorination system is the destruction of pathogenic micro-organisms in order to prevent the transmission of disease through contamination of the receiving stream. Downstream use of the receiving stream for potable water supply, for swimming, for livestock water supply, or for irrigation of crops presents an avenue for the transmission of disease unless adequate disinfection is provided.

Raw domestic wastewater contains many millions of micro-organisms. Many of these micro-organisms are not harmful to human health and some are even essential to the success of biological wastewater treatment processes. However, a relatively large number of pathogenic organisms, including bacteria, viruses, and amoebic cysts, are capable of producing serious illness and disease in humans. Because of the large number of micro-organisms present and the resistance of certain organisms, enough pathogenic organisms may survive and remain in the treated effluent to create a health hazard to downstream users.

Disinfection is utilized to further reduce the number of micro-organisms present in the treated effluent and minimize the potential for contamination of the receiving stream.

Process Description
The Huntington Wastewater Treatment Plant utilizes a chlorination system to provide disinfection of the final effluent prior to discharge. Chlorination is the most widely used disinfection process and years of experience have proven it to be an effective and reliable disinfection alternative.