WASTEWATER TREATMENT
The Town of Forest City, North Carolina began a comprehensive wastewater treatment program with the construction of the Riverside Drive Water Reclamation Facility in 1959. Operations began in 1960 with improvements in 1983, 1988, 1991 and 1997. Design capacity is 3 million gallons per day (MGD), with a peak of 7 MGD; current flow is 4 MGD. Daily treated flow of 40,000 gallons is reduced by drying and will eventually be applied to farmlands in Rutherford County.
1995 Aerial Photo of Water Reclamation Facility
**See narrative below for numbered facility components.
WASTEWATER TREATMENT: FROM START TO FINISH
53 miles of underground pipes carrying domestic and industrial wastewater converge at the:
1. Headworks Building
This houses a mechanical bar screen and grit/grease removal system which removes the larger solids and readies the flow for entry into the First-Stage Aeration Basins
2. First-Stage Aeration Basins
These two basins provide an optimum oxygen supply for decomposition of the sewage by bacteria. The flow is regularly checked for nutrients, pH, solids, pathogens, metals and organic chemicals. The flow then enters the large Second-Stage Aeration Basin.
3. Second-Stage Aeration Basin
Here further oxygenation and decomposition occur. A complex group of micro-organisms break down (feed on) on the suspended or dissolved organic impurities remaining in the water. No chemicals are used throughout this decomposition process, only the natural action of many bacterial species.
4. Clarifiers
From the big basin flow gravitates to two clarifiers, the round settling tanks. Remaining solids settle, and most are returned back to the aeration basins at a rate of 1.3 MGD. The clear top layer in the clarifiers is then chlorinated to destroy pathogens, then de-chlorinated with sulfur dioxide prior to release to Second Broad River. This effluent meets or exceeds all EPA requirements for biological oxygen demand rates.
THE DISPOSAL: BIOSOLIDS RECYCLING
5. Aerobic Digesters
40,000 gallons daily of treated flow are "wasted" to 3 aerobic digesters. These bacterially-active basins further oxygenate and decompose the sludge. It is then pumped to a 2 meter belt press for de-watering into a "cake" material. This Class B cake leaves the press averaging 13.5% bio-solids, and can be spread safely on permitted farmland by proper equipment. Nutrients and metals are monitored to meet EPA guidelines.
6. Class A Bio-solids, an Innovation:
In 1997 the Town invested one million dollars to add a gas-fired drying system which enables the Class B bio-solids to be regulated under Class A. Once dried this low-grade fertilizer supplement averages 90% solids and can be spread safely on farmland and other areas without restriction.
7. Office and Laboratory:
Quality control is insured with this on-site laboratory where personnel conduct daily tests including suspended solids, total solids and biochemical oxygen demand. This analysis of certain parameters makes sure that the treatment process is working effectively. Samples from the aeration basins are monitored for micro-organism populations that indicate how well the decomposition process is working and any need for adjustment. Wastewater coming into the plant is tested for metals and nutrients (nitrogen and phosphorus); fecal coliform and certain organic compounds (solvents and hydrocarbons) are monitored on a regular basis.
Staffing: This complex operation is currently staffed by seven trained operators. Automation is an important part of the system and helps the staff to maintain optimum conditions throughout the plant.
ENVIRONMENTAL QUALITY
The citizens of Forest City can be proud of the high standards and excellent environmental record of this facility. The Town is committed to protect the environment and provide this essential service in a cost effective and safe manner.
DESIGN INFORMATION
Design capacity: |
5 MGD; peak 7 MGD |
Current flow (discharge): |
3 MGD |
Effluent BOD: |
10mg/L dialy averag |
Septage receiving station: |
10,000 gal. Capacity |
Bio-solids annual production: |
2,000 cu. Yds. / 250 Dry Tons |
Bio-solids silo storage capacity: |
200 cu. Yds. / 125 Dry Tons |
Dryer storage time: |
60 days |
Population served: |
8,500 domestic customers 5 major industries |
| Bio-solids are available for public use at a low cost. | |
For more information or to schedule a tour contact:
WRF Superintendent
P.O.Box 728
Forest City, NC 28043
Phone: 828-248-5217
Fax: 828- 247-1626
Email: wwtp@townofforestcity.com
Forest City's Pretreatment Program spenson@townofforestcity.com
Information request for Forest City's Oil and Grease Program jdotson@townofforestcity.com
Location of Facility: Corner of Riverside Drive and Old Caroleen Road
Directions: From Highway 74 bypass take the Old Caroleen Road exit, which is about 2 miles east of Exit #182. Go north one mile. Turn right onto Riverside Drive. Facility is on the right.
