This page contains resources applicable to dewatering operations in the construction phase.  The goal of these tools is to optimize and oversee dewatering operations to prevent water pollution and promote compliance with Appendix G, Hawaii’s National Pollutant Discharge Elimination System (NPDES) General Permit Authorizing Discharges Associated with Construction Activity Dewatering. The tools will also serve as a guide for assigning roles and responsibilities to staff for better preparation in handling dewatering related operations.

For all categories, non-storm water from dewatering activities shall not be discharged from the site unless an Appendix G NPDES Permit has been issued.  Don’t have an NPDES permit, but need one?  See the Design Dewatering Tools Page.


Process for Construction Dewatering

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Daily Awareness & Visual Inspection

Weekly or Per-Discharge Sampling

Submitting Any Required Monitoring Reports

Reporting Exceedances (If Occurred)

Closing the Permit

Construction Process for Projects with NPDES Dewatering Permits

The flow chart to the right shows the general construction timeline of dewatering activities for projects under coverage of the Appendix G NPDES Permit.  This tool also includes a Dewatering Effluent Assessment Guide for assistance in determining the quality of the discharged water.

Monthly Review Sheet for NPDES Dewatering

The worksheet to the right includes certain pertinent items that should be monitored while a project is covered by the Appendix G NPDES permit.  This report is not mandatory, but is intended to assist the Project Manager in knowing what to look for and keep track of while dewatering operations are active.

Discharge Monitoring Reports

The tools in this section can be used to fill out and submit Discharge Monitoring Reports (DMRs).

DMRs are required monthly for projects covered under an NPDES General Permit (Appendix G) or Individual Permit for Construction Dewatering Discharges.

Monitoring results from one month must be received by the Department of Health (DOH) by the 28th day of the following month. For example – monitoring performed in June must be submitted by July 28.

  • No Discharge?  Submit a DMR even if there are no discharges during the monitoring period.
  • Multiple Discharges? If there is more than one discharge in a single month, report the monthly minimum, maximum and averages for each parameter.  For pH, only report monthly minimum and maximum.
  • Continuous discharge? Samples should be taken at least once per week.

All submissions must be submitted to DOH’s E-Permitting Portal

Dewatering Non-Compliance

The guide to the right can be used to prepare the oral and written reports made to the DOH-CWB when a dewatering non-compliance occurs (e.g. violation of an effluent limitation, unanticipated bypass or upset, failure to submit DMRs or laboratory results, etc.).

Note: Notify the DOH-CWB Enforcement Section at 808-586-4309, or if outside of office hours, call the Hawaii State Hospital Operator at 808-247-2191, within 24 hours once aware of the following:
  1. Violation of an effluent limitation specified in Table 34.5 or a basic water quality criteria specified in section 6(b) of the Appendix G NPDES permit;
  2. Discharge or noncompliance with effluent limitations which may endanger health or the environment; or
  3. Unanticipated bypass or upset

E-Permitting Guide for Notice of Cessation

A Notice of Cessation (NOC) must be submitted when terminating your Notice of General Permit Coverage (NGPC) or NPDES Individual Permit.  The guide to the right can assist with navigating DOH’s E-Permitting Portal to do so.  By submitting an NOC, you are certifying that:

  1. You want to terminate your NGPC or NPDES permit; and
  2. You acknowledge that you are no longer authorized to discharge from the facility

NOC submissions should include the following items (see the E-Permitting Guide for NOCs to the right for details):

  1. An electronic copy via DOH’s E-Permitting Portal; and
  2. A hard copy package, including (i) the signed NOC with wet signature, (ii) a signed transmittal/certification form from the E-Permitting Portal, and (iii) a CD/DVD or thumb drive with scanned copies of the aforementioned, via mail to the following address:

DOH Clean Water Branch
Hale Ola Room 225
2827 Waimano Home Road
Pearl City, Oahu, HI, 96782

Note:  The address provided in the Appendix G NPDES Permit is no longer current – please mail submissions to the address above.


Please contact The Limtiaco Consulting Group should you have any questions or require any assistance. Your feedback regarding any of the tools and information featured here is gladly appreciated.

The Limtiaco Consulting Group
(808) 596-7790