Alaska Excavation Dewatering Permit (6-AK-e)
The General Permit for Excavation Dewatering authorizes dewatering of groundwater and stormwater that accumulates within an excavation area in all regions of the state, with the exception of the Denali National Park and Preserve and the Indian Reservation of Metlakatla.
More specifically, the general permit authorizes:
- Excavation dewatering associated with construction activity where pumps, sumps, etc. are used within or near the excavation areas to remove accumulated groundwater, surface water, and stormwater; or
- Groundwater dewatering through the installation of temporary dewatering wells, vacuum well points, eductors, etc. to cause the localized lowering of the surface water table to facilitate construction activity.
Excavation dewatering discharges must be made in accordance with effluent limitations, monitoring requirements, and other conditions set forth within the General Permit. General Permit for Excavation Dewatering, p.5.
If the project will involve pumping water from excavation areas, the developer will also likely need to obtain a temporary use of water permit from the Alaska Division of Mining Land and Water (DMLW). For more information on the DMLW’s process for issuing a temporary use of water permit, see:Temporary Use of Water Permit:
Excavation Dewatering Permit Process
6-AK-e.1 to 6-AK-e.2 – Is the Discharge Eligible for Automatic Authorization Under the General Permit for Excavation Dewatering?
Alaska’s General Permit for Excavation Dewatering may automatically authorize certain excavation dewatering discharges unless the excavation dewatering activities will result in:
- Discharges to waters of the U.S.;
- Discharges located within 1,500 feet of a DEC-identified contaminated site or contaminated groundwater plum with discharges to land or to waters of the U.S.; or
- Discharges to waters of the U.S. greater than 1,500 feet from a DEC-identified contaminated site or contaminated groundwater plume and not eligible for coverage under the ‘’’Construction General Permit’’’.
If the General Permit automatically authorizes the excavation dewatering discharge, the developer is not required to submit a Notice of Intent (NOI) or Best Management Practices (BMP) Plan to the Alaska Department of Environmental Conservation. However, the developer must still comply with the control measures, land disposal discharge requirements, and reporting and recordkeeping requirements outlined in parts 4.0, 5.1, and 6.0 of the General Permit. General Permit for Excavation Dewatering, part 2.1.3.
6-AK-e.3 – Notice of Intent; Best Management Practices Plan
If the excavation dewatering discharge is not eligible for automatic authorization under the General Permit, the developer must submit a completed Notice of Intent (NOI) and certified Best Management Practices (BMP) Plan to the Alaska Department of Environmental Conservation (DEC) at least 30 days prior to the date the discharge is to commence. General Permit for Excavation Dewatering, part 2.2.1.
The developer may submit the NOI electronically via the DEC’s Water Online Application System or complete a paper form available at the DEC’s APDES Storm Water Forms Webpage. General Permit for Excavation Dewatering, part 2.2.3. The DEC strongly encourages developers to use the eNOI system to expedite processing of the developer’s request.
Notice of Intent
- Must be signed by the developer in accordance with the Signatory Requirements (see General Permit for Excavation Dewatering, Appendix A, part 1.12;
- Must contain a general location map with sufficient detail to identify the location of the discharge and waters of the U.S. within one mile of the site; and
- Must be accompanied by the appropriate fee, as established by 18 AAC 72.956.
Best Management Practices Plan
The BMP Plan:
- Must be signed and certified by the developer in accordance with the requirements of General Permit for Excavation Dewatering, Appendix A, part 1.12 and must include the following:
- A description of how the developer will manage the wastewater and implement the BMP on-site;
- A description of the land disposal site conditions such as soils, topography, drainage patterns, depth to groundwater, and existing vegetation; and
- A detailed site map to scale showing the discharge points, infiltration areas, drainage boundaries, flow direction of discharged water, location of all waters of the U.S. on site and those located within 2,500 feet of the site boundary, and location of BMPs to be implemented.
Contaminated Site or Contaminated Groundwater Plume
If the discharge will occur within 1,500 feet of a DEC-identified contaminated site or contaminated groundwater plume, the developer must also:
- Identify potential pollutants of concern that may be present or become present in the excavation dewatering discharge based on the excavation dewatering activity;
- Identify a proposed treatment methodology to be incorporated into the BMP plan if contaminants can become entrained in the excavation dewatering and the contaminant discharge concentrations;
- The DEC may also request a hydrogeological report unless the developer can demonstrate that the contaminated site(s) within 1,500 feet of the dewatering activity does not affect the groundwater within the dewatering area of influence.
For more information on the requirements to discharge at a contaminated site, see General Permit for Excavation Dewatering, part 2.2.7.
6-AK-e.4 to 6-AK-e.6 - Review Notice of Intent and Best Management Practices Plan
Upon receipt, the DEC initiates review of the developer’s NOI and BMP Plan. During the review period, the DEC may notify the developer that additional action must be taken before the DEC can issue an excavation dewatering authorization, based on concerns regarding the project’s eligibility for authorization under the General Permit. General Permit for Excavation Dewatering – Permit Fact Sheet, part 3.2.4.
6-AK-e.7 to 6-AK-e.8 – Will the Discharge Occur Within 1,500 Feet of a Contaminated Site or Contaminated Groundwater Plume?
The General Permit contains standard conditions that must be included an excavation dewatering authorization. The standard conditions cover requirements such as monitoring, recording, reporting requirements, compliance responsibilities, and other general requirements. General Permit for Excavation Dewatering – Permit Fact Sheet, part 3.8.
If the discharge will occur within 1,500 feet of a DEC-identified contaminated site or contaminated groundwater plume, the DEC may apply special permit conditions and impose additional requirements, such as additional monitoring and sampling requirements. The special conditions provide assurance that the developer’s dewatering activities do not pull contamination from known contaminated sites. General Permit for Excavation Dewatering – Permit Fact Sheet, part 3.3.3.
6-AK-e.9 – Excavation Dewatering Authorization
Once the DEC approves the developer’s application, the DEC will assign a specific authorization number for the excavation dewatering discharge and provide the developer with written notice of the authorization. The authorization allows the developer to discharge excavation dewatering under the terms and conditions of the permit on the date specified in the authorization letter. The developer may not discharge excavation dewatering until the developer receives written notification that the DEC has granted the authorization and assigned an authorization number. General Permit for Excavation Dewatering, part 2.1.1.
6-AK-e.10 - Continue With Excavation Activities
During excavation of the project site, the developer must:
- Comply with the requirements of the General Permit’s Standards and Limitations; and
- Select, install, implement and maintain control measures at the dewatering project site that minimize pollutants in the discharge as necessary at the point of discharge.
The developer may also be required to comply with site-specific special conditions or stipulations, depending on the unique factors of the project, location, etc.
Authorized excavation dewatering discharges are also subject to the limitations, inspections, and monitoring requirements established by General Permit for Excavation Dewatering, Part 5.0 Limitations, Inspections, and Monitoring Requirements.
6-AK-e.11 – Notice of Termination
Within 30 days of completing the excavation dewatering, the developer must submit a Notice of Termination (NOT) to terminate coverage under the permit. The authorization expires at midnight on the signature date of the NOT. General Permit for Excavation Dewatering, parts 2.1.2 and 7.0.
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- Alaska Pollutant Discharge Elimination System – General Permit for Excavation Dewatering, Permit Number AKG002000
- Alaska Division of Water - General Permit for Excavation Dewatering – Permit Fact Sheet
- Alaska Division of Water - Water Online Application System
- Alaska Division of Water - APDES Storm Water Forms Webpage
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