Clean water is critical for sustaining life, yet polluted water and inadequate sanitation kills at least two children every minute worldwide. And even in the United States, where wastewater treatment is relatively advanced compared to some countries, many people take the flow of water in and out of their homes for granted. Where does it all go after we flush the toilet or pull the plug on the drain? What's more, how does this used water get cleaned and safely find its way back into the environment?
The answer is your local wastewater treatment facility, which operates 24/7 to make sure your community's wastewater is treated properly and released back into waterways such as lakes, streams, rivers, where it flows to one of the great oceans or lakes. It can also be used again along the way for irrigation, commercial or residential use, groundwater replenishment, and even drinking water, or it evaporates into the atmosphere and returns as rain in some other part of the world. Water is used over and over again, and thousands of water quality professionals around the world work to protect its quality and cleanliness.
Public Works & Utilities Sewage Treatment Division operates and maintains four (3) Wastewater Treatment Facilities and sixty-eight (68) Sanitary Sewer Lift Stations. These facilities provide primary, secondary, and advanced wastewater treatment, along with disinfection prior to discharge. These facilities operate under permits to discharge treated wastewater, which are issued by the Kansas Department of Health and Environment that sets forth specific discharge criteria that is protective of Public Health and the Environment.
The Lower Arkansas River Water Quality Reclamation Facility has design capacity to treat 54.4 million gallons per day (MGD) of wastewater.
After completion of treatment, flow from this facility (effluent) is discharged into the Arkansas River.
The Four Mile Creek Water Quality Reclamation Facility is designed to treat 3.0 MGD of wastewater and discharges into Four Mile Creek, which is a tributary of the Walnut River. In 2019, the facility was upgraded to 6.0 MGD average design flow.
The facility is performing biological nutrient removal creating an effluent that is low in phosphorus and nitrogen.
The Four Mile Creek Wastewater Treatment Facility and collection system along with the West Sedgwick County Sewer District were acquired by the City of Wichita from Sedgwick County in April of 2001.
The Cowskin Creek Water Quality Reclamation Facility has been operational since March of 2003, and is designed to treat 2.0 MGD.
The discharge from this facility is received by two ponds that are available for recreational fishing to the public.
The treated water is then discharged into Cowskin Creek.
The process incorporates advanced treatment technology, including biological nutrient removal, tertiary filtration, and ultraviolet disinfection.
Pretreatment and Biosolids
Industrial Pretreatment & Wastewater Laboratory Programs
As part of Wichita's NPDES Permit to discharge treated sewage to the Arkansas River, the City is required by the US Environmental Protection Agency to implement and enforce the Federal Pretreatment Regulations which include pollutant discharge standards for categorical industries (e.g. Metal Finishers, Foundries, Circuit Board Manufacturers, Oil Refineries), as well as general regulations for all Significant Industrial Users (SIU).
The City regulates all local industries which discharge pollutants into the sanitary sewer that may cause any interference or damage to the municipal sewage conveyance and treatment system, or cause the City's sewage treatment plant to violate its NPDES Permit limitations.
These requirements place the City in the position of being a service provider and a regulator. The Wichita Water Utilities strives to perform both duties well, by providing excellent water and sewer service to its customers and by enforcing all Pretreatment Regulations in a fair and equitable manner.
To determine if an industrial process will be regulated by the City, first determine if the industry qualifies as a Significant Industrial User. If the industry meets the SIU criteria, then it must be issued an Industrial Wastewater Discharge Permit by the City. The Permit will contain certain conditions and requirements the industry must meet to maintain compliance with all Federal, State, and local Pretreatment Regulations.
General SIU criteria is as follows:
- The industry discharges at least 25,000 gallons per day of wastewater to the sanitary sewer.
- The industrial process is identified as one of the Federal Pretreatment Categorical Industries. For a list of categorical industries, contact the Pretreatment Office at (316) 303-8703.
- The industry discharges a pollutant which could cause interference or damage to the Publicly Owned Treatment Works (POTW) or negatively impacts the receiving waters upon discharge or sewage sludge disposal requirements.
- The industry discharges a waste stream which the Director of the Water & Sewer Department has reasonably determined requires issuance of a Industrial Wastewater Permit to Discharge.
All SIUs permitted by the City are subject to a permit fee which is based on the industrial wastewater daily flow rates. Your best course of action is to contact the City's Pretreatment Office at (316) 303-8703 and let them evaluate your need for a permit.
2015 Pretreatment Workshop was held Nov. 19th. Topics included Commercial Water and Sewer Billing, Asset Management, Flow Meters and OSHA's SHARP program. Copies of the presentations are provided below:
Extra Strength Sewage Billing Program
In has a sewage surcharge program called the Extra Strength Program. If the industry discharges waste which contains high concentrations of treatable pollutants, then the industry is sampled and billed on a monthly basis for the treatment of this "extra strength" waste. This assures that the treatment and disposal costs associated with wastewater with conventional pollutant concentrations higher than residential wastes, will be paid for by the industry rather than the residential customer. Conventional Pollutants billed by the Water and Sewer Department are:
- Biochemical Oxygen Demand
- Total Suspended Solids
- Oil and Grease
These are current inside the City rates and are assessed per pound per month based on the volume discharged and the analytical results of the samples collected during the monthly billing cycle. Outside the city rates are approximately 55% higher.
Sewer Service Usage and Billing
Your monthly sewer usage charge is based on the amount of City water consumed during the billing cycle. However, if the industry supplements its City water usage with well water and discharges the total to the sewer, then the industry must either meter the well water consumed or install a totalizing meter at the point of wastewater discharge into the City sewage collection system.
Many industries discharge less water than what is consumed, as a result of water going out in the product (e.g. commercial bakeries, soft drink manufacturers, concrete companies), or water evaporated during operations (e.g. boilers, cooling towers). In order to receive credit on the sewer bill, the industry must request that the City install a meter at the water which is not being discharged or request that the City install a meter a the point of wastewater discharge into the City sanitary sewer.
Remedial Groundwater Discharge Program
Some facilities have contaminated groundwater which must be treated and discharged. The City prefers that these businesses seek other alternatives than the sanitary sewer to discharge the groundwater. However, as a temporary measure, the City may accept the treated groundwater if it meets Pretreatment Discharge Standards and capacity is available in the sanitary sewer. The discharge period is limited to a maximum five year term with annual permit renewals required. The business is required to monitor the discharge to assure that it meets pretreatment requirements. For Permit monitoring and fee requirements, contact the Pretreatment Office.
Every day the Sewage Treatment Laboratory analyzes over 50 samples collected by various processes at the four wastewater facilities to assure that the plants are operating in full compliance with regulatory discharge requirements. The rivers and streams that receive the plants effluent discharges are also monitored. The laboratory must meet stringent laboratory certification criteria, and by doing so is certified by the National Environmental Laboratory Accreditation Program.
What are Biosolids?
Biosolids are the nutrient-rich organic product of wastewater treatment. A beneficial resource, biosolids contain essential plant nutrient and organic matter and are recycled as a fertilizer and soil amendment.
Wastewater treatment processes are taken right out of nature's recipe book. In streams and lakes, natural aeration helps to purify the water while microorganisms break down solids. Wastewater treatment uses the same idea; the liquid portion is treated and returned to streams, lakes, or oceans, and the solids are further processed into stable organic material, called biosolids.
Everyone contributes directly or indirectly to biosolids. Both businesses and households, whether connected to sewer systems or on septic tanks, generate biosolids. Today, modern treatment processes and strict controls on discharges to sewers contribute to high quality, recyclable biosolids.
The Public Works & Utilities Sewage Treatment Division operates a biosolids land application program which results in approximately 20,000 tons of biosolids applied annually on almost 500 acres of agricultural land that is used to raise crops such as corn, soybeans and wheat.
Biosolids contain essential plant macronutrients (used by plants in large amounts) including nitrogen, phosphorus and sulfur, as well as plant micronutrients (required in smaller amounts) such as zinc and copper. Applications of biosolids allow these nutrients to enter the soil for plant use. Biosolids are retained in the soil and release nutrients slowly as they are needed by plants. Appropriate applications of biosolids prevent nutrients from leaching beyond the plant rooting zone into the groundwater.
Biosolids applications promote plant root growth and generally help plants to grow greener, more vigorously and often with improved yields. The dense crops grown by biosolids create large amounts of straw and other organic matter that can be tilled back into the soil, improving soil moisture retention and erosion resistance, as well as increasing natural earthworm populations. Recent studies have shown that organic matter used in agriculture helps suppress plant disease. The addition of biosolids can also help to moderate highly alkaline or acidic soil conditions.
Biosolids have been recycled on pastureland, dryland wheat, soybean, and corn in area farmlands surrounding Wichita. Application rates are carefully designed to meet the needs of individual crops. Dewatered biosolids are typically applied with calibrated manure spreaders and tilled into the soil.