The 82nd State General Assembly passed legislation which required the Department to write new rules and a provide issuance of a General Permit to authorize well construction and well services related wastewater discharge when that discharge reaches a Water of the United States.
Starting on March 17, 2010, all well construction, well related service and GHEX loop borehole drilling related wastewater that reaches a Water of the United States is regulated by a new National Pollution Discharge Elimination System permit (NPDES) designated General Permit #6 or GP6.
What is well construction wastewater?
Well construction wastewater is the wastewater generated by any well drilling related activity in our state. These activities include new well construction, existing well rehabilitation and renovation, pump installation, test pumping, geothermal borehole and well drilling, and other types of drilling that access or use the groundwater for a specific purpose. This wastewater can be made up of drilling fluids or groundwater, and can be very turbid and contain geologic material or consists of nearly clear groundwater. If the well drilling related discharge leaves the construction site it becomes wastewater discharge.
Anytime the wastewater generated by well related construction and services discharges off-site and reaches a Water of the United States, the wastewater falls under the requirements stated in GP6. GP6 requires that the wastewater must adhere to the treatment standards and discharge requirements stated within the general permit. If the well construction or well services related wastewater does not reach Waters of the United States, the discharge is not subject to GP6.
Why is well construction and well service related wastewater regulated?
Many well sites are located in close proximity to waterways or other conveyances that allows the wastewater to reach a Water of the United States. This wastewater normally consists of drilling fluids and/or groundwater, and contains particles of natural materials like sand, silt, colloids (clays), limestone and dolomite, and possibly various chemical drill fluid enhancements. When allowed to flow untreated, the wastewater will eventually reach a stream, river or a lake. This can result in turbidity that can affect aquatic life and sedimentation that can create long term changes to the stream or lake bed.
In addition, drilling fluid additives and other products used in borehole construction and well servicing may contain substances that are acutely toxic when released in a water body. These products can chemically and physically alter the receiving water and cause additional problems, such as killing the aquatic life present in the water and inhibiting the life processes for all species that depend on the water. In addition, untreated well related wastewater affects the use and enjoyment for adjoining property owners and any citizens who can access the water.
Well construction discharge at the point of stream entry. |
Well construction discharge after mixing - downstream 200 feet. |
What well services are included in the GP6?
- All types of new water supply well construction including:
- Private and public water drinking water supply wells
- Non-potable use wells such as irrigation wells, plant process water supplies and dewatering wells
- Geothermal use water supply wells
- Groundwater injection return wells (geothermal injection wells)
- Geothermal loop borehole construction
- Compressed air/gas injection well construction
- All types of services performed on existing wells, like renovation or rehabilitation services
- All types of well pump repair on all types of water wells when the well will be pumped to waste
- Development, rehabilitation and test pumping on new or existing water supply wells
What well services are not included in GP6?
- The actual production pumping and on-going operation of dewatering wells - please contact your local Field Services Office for additional information on discharge standards for these types of activities.
- The construction of oil and gas test wells and production wells - please contact the Iowa DNR
How do I comply with GP6?
Iowa's NPDES General Permit No. 6 requires the development of a well site specific well water pollution prevention plan (WWPPP or Plan) for the each well construction site where the discharge reaches a Water of the United States. When an engineer is used to develop the well plans, an engineer must also develop and create the WWPPP for the permittee. For wells that do not require the services of an engineer, the WWPPP can be developed by the well/landowner (permittee) or by a contactor or agent retained by the permittee to manage the WWPPP.
The WWPPP for the well construction or service event must be designed to address the anticipated treatment needs for the wastewater that will be generated by the well project and then provide guidance for the implementation, inspection, and maintenance of any Best Management Practices (BMPs) or controls specified in the Plan. The Plan shall be written to adequately treat the wastewater before it enters conveyances, streams, rivers, and lakes and before it causes environmental problems. As the work on the well project is about to begin, the local regional IDNR Field Services Office must be notified using the Field Office Notification Form (FON).
The Plan shall take into account items that will influence how the wastewater is managed, like:
- The location of the well on the landscape;
- the potential protections and the limitations that the landscape may provides for natural wastewater treatment;
- the potential quantities and anticipated qualities of wastewater that may be generated during each phase of the well construction or service work;
- the best management practices (BMPs) used both on and off of the construction site to treat the wastewater;
- the type of BMPs that will be applied to the site and strategic locations of all BMPs used;
- any adjustments or changes made to the BMPs after the initial installation;
- who inspects the BMPs, how often the inspections are performed, and what is found during the inspections;
- and certification that all permittees and co-permittees fully understand what is required under GP6.
What resources are available?
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PDF |
| General Permit #6 |
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| Summary guidance - Guidance Document for Well Construction and Well Service Discharges A brief Guide to Developing a Well Water Pollution Prevention Plan and Using Best Management Practice |
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| BMP Guidance |
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| Field Office Notification Form, #542-0018 |
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| Co-permittee Certification Roster - Appendix A (Required Form) |
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| Well Discharge Wastewater Inspection Form - Appendix B (Required Form) |
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| Will My Well Discharge Require General Permit #6? |
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How can I find out new information on well construction discharge wastewater as soon as it is made available?
You can have updated Well Discharge Wastewater Information from the DNR sent directly to your email inbox as soon as the information is made available.
Well Discharge Listserv: The Well Discharge listserv will automatically send updates to your email inbox whenever the department has new information to distribute. This information is targeted to those who actively engage in the design and/or construction of water supply wells and geothermal wells/boreholes and those who design, install and manage the BMPs and controls used to treat well discharge wastewater. Once you subscribe, you will receive regulatory news, program updates and technical guidance as well as training opportunities in this program area.
Who can I contact for additional information?
For information about GP6 and other associated documents please contact:
Russ Tell - phone: 515-725-0462, russell.tell@dnr.iowa.gov
Iowa DNR Water Supply Engineering
401 SW 7th Street, Suite M, Des Moines, IA 50309-4611
Wendy Hieb - phone: 515-281-7804, wendy.hieb@dnr.iowa.gov
Iowa DNR NPDES Wastewater Permits
502 E 9th Street, Des Moines, IA 50311
Who should I contact if I suspect that a stream, river, or lake is being impacted by water well related wastewater discharge?
You should contact your local regional IDNR Field Services office. Please use the link below to determine the correct Field Office for your location and obtain the Field Office contact information.
Useful web links:
Please check back periodically to obtain the latest information regarding well discharge wastewater or consider subscribing to the well discharge wastewater listserver.