Construction with Dewatering FAQ

Can I discharge water from groundwater dewatering operations under this permit?

Yes, if you selected dewatering operations and meet the following requirements:

The property is either:

1. not identified as a contaminated site and there is no identified contaminated site within 500 feet,
2. identified as a contaminated site, but documentation confirms that the contamination has been remediated, or
3. the pollutants of concern are not present in groundwater at the project site at concentrations equal to or greater than the surface water criteria in Rule 62-302.530, F.A.C.

What if I suspect the discharge from dewatering operations are from a contaminated site?

If a discharge from dewatering operations causes or contributes to a water quality violation, the permittee shall contact the department. This permit authorizes the discharge of only uncontaminated groundwater.

A site that does not meet the conditions of Part 3.4.3 of the CGP may qualify for coverage under Rule 62-621.300(1), F.A.C., or under an individual wastewater permit on the appropriate form listed in Rule 62-620.910, F.A.C. Operators should contact the appropriate DEP District Office wastewater permitting program for questions on wastewater permits.

What dewatering BMPs must I use?

Required dewatering BMPs are found in the State of Florida Erosion and Sediment Control Designer and Reviewer Manual (2013)

If I am the operator of the CGP can I transfer responsibility to the organization conducting the dewatering operation?

No, NPDES stormwater permits are nontransferable. The responsible authority is liable for all activities indicated on the NOI.

Note: All subcontractors identified in the SWPPP must sign a copy of the following certification statement before conducting any construction activities at the site. The certifications must have the name and title of the person signing the certification; the name, address, and telephone number of the contracting firm; and the signature date.

"I certify under penalty of law that I understand, and shall comply with, the terms and conditions of the State of Florida Generic Permit for Stormwater Discharge from Large and Small Construction Activities and this Stormwater Pollution Prevention Plan."

If I applied for the new 2015 CGP and did not indicate dewatering operations, can I modify my NOI to include it?

You must either obtain a Dewatering Generic Permit through your local DEP District Office or temporarily stabilize your site, reapply for the construction generic permit with dewatering operations and terminate your existing coverage.

What are dewatering activities?

For the purposes of this construction generic permit, dewatering means temporarily lowering the ground water level, whether confined or unconfined, by mechanical pumping to allow for construction and excavation activities at the construction site covered by this generic permit. 

How do I determine if my site is uncontaminated?

You may use the DEP Contamination Locator Map (CLM) and DEP's Institutional Controls Registry (ICR) Web Viewer to determine cleanup restoration status. Please note: These links will open in a new Browser window.

• Contamination Locator Map (CLM - Mapping Application)
• DEP’s Institutional Controls Registry (ICR - Web site)
• DEP’s Institutional Controls Registry (ICR - Mapping Application)

Note: The permittee may use other information available to them to complete the NOI such as Environmental Assessments which is common in real estate transactions and bank loans.

What is backwash?

Water used in the cleaning/flushing of various media filters used during dewatering activities.

Note: Backwash water should be managed such that it is not discharged directly to waters of the state or an MS4. Backwash water may be hauled away for proper disposal or returned to the beginning of the treatment process.