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NPDES General Permit #9

for Dewatering Activities and Residential Geothermal Discharges



The department is developing a new general permit. This permit would authorize discharges from the following activities:

  • Excavation dewatering associated with construction activity
  • Temporary groundwater dewatering to facilitate construction activity
  • Residential open-loop geothermal heating and cooling systems

The permit would cover dewatering discharges to surface waters of the state and to the ground surface.  Discharges from geothermal systems that do not reach navigable waters are already exempted by rule from obtaining operation permits.  Therefore, only discharges to navigable waters from residential geothermal systems will by authorized by the new permit.

Draft General Permit #9 – October 12, 2017


Currently, people conducting discharges that would be authorized by the permit can either pursue an individual permit or discharge illegally.  Obtaining an individual permit requires an investment of time and money that is disproportionate to the impact these discharges usually have on the environment.  Not only is discharging without a permit illegal, but the discharges may occur without environmental controls.  DNR receives many requests for guidance from those who are interested in avoiding negative environmental impacts.

This permit will benefit dischargers by providing them a permit shield without the time and cost of obtaining an individual permit.  Unlike individual permits, no fees are associated with GP#9.  It also provides dischargers with guidance for minimizing the impact of these discharges on water quality.  This permit will benefit the environment by providing requirements and guidance for conducting these discharges in a manner that will avoid negative impacts on water quality.  This permit will benefit DNR by providing a mechanism to authorize these discharges using very little staff time, which can then be spent on higher-risk discharges.

What this permit will do:

  • Authorize temporary and limited discharges that can meet water quality standards.
  • Authorize certain discharges that are not temporary and limited but that are approvable under Iowa’s Antidegradation Implementation Procedure.
  • Provide a permit shield to authorized discharges.
  • Establish eligibility requirements and best management practices to ensure protection of water quality.
  • Reduce the number of permittees required to pursue individual permits.
  • Greatly reduce the amount of time needed to obtain permit coverage for most permittees.

What this permit will NOT do:

  • Authorize discharges that will cause violations of water quality standards.
  • Authorize discharges from groundwater remediation systems.
  • Authorize discharges to Outstanding Iowa Waters or state-owned lakes.
  • Establish burdensome notification requirements.
  • Require fees.
  • Eliminate the department’s ability to require a discharger to apply for an individual permit.
  • Eliminate a discharger's ability to apply for an individual permit.


General permits must be adopted into rule.  Most importantly, the discharges authorized by the permit must be added to the list at 567 IAC 64.3(4) and the permit must be added to the list of general permits at 567 IAC 64.15.  Other rule changes may also be necessary.  This page will be updated as rulemaking proceeds.

Stakeholder Input:

DNR has held three stakeholder meetings on the draft permit.  The presentation and notes from the stakeholder meetings are linked below.

Proposed General Permit #9 Presentation from 5-20-2015 Stakeholder Meeting
Notes from 5-20-2015 Stakeholder Meeting for Proposed GP #9
Notes from 5-3-2016 Stakeholder Meeting for Proposed GP #9

More Information:

For additional information on DNR's water quality standards, please see 567 IAC Chapter 61.

For additional information on DNR's Statewide Standards for Contaminants in Soil and Groundwater, please see the DNR Cumulative Risk Calculator.

For more information on the development of this permit, please contact Julie Faas at 515-725-8409 or julie.faas@dnr.iowa.gov.