CommonDewateringPermits&Requirements

Which Dewatering Permit Do I Need?

Are you dewatering

surface water or groundwater? Are you dewatering only

accumulated stormwater? No

Yes

STORMWATERDISCHARGEPERMIT

(GENERALCONSTRUCTIONPERMIT)

COR030000&COR400000

Yes

� BMPs must be sufficient to prevent

contamination of waters of the State.

� Any site over 1 acre should already be

covered under this permit with the

State (CDPHE).

� Allows dewatering of accumulated

stormwater on site.

� Must update SWMP to identify de-

watering locations.

� Dewatering of groundwater to state

waters or storm sewer systems is not

covered under this permit.

Is the Groundwater

Contaminated?

No

Yes

CONSTRUCTIONDEWATERINGPERMIT

COG070000&COG080000

� Allows dewatering of groundwater, surface

water, and comingled stormwater.

� Permit application must be submitted to

CDPHE at least 30 days before the

anticipated dewatering activity.

� Water quality sampling must be submitted

to CDPHE.

� Installed BMPs must meet effluent limits

defined in permit.

� Dewatering filter bags must not be placed

directly in water ways.

� Permit exceedances must be reported to

CDPHE

� Dredging and filling in waters of the State

requires a separate 404 permit with the

Army Corps of Engineers.

� A permit is not required for clear water

diversions.

� Dewatering of groundwater that does not

leave the site is covered under the Low

Risk Discharge Guidance Discharges for

Uncontaminated Groundwater to Land.

REMEDIATIONOFGROUNDWATERPERMIT

COG315000,COG317000,COG318000

� Allows dewatering of contaminated

groundwater under specific

remediation activities.

� Permittee must refer to permit for

guidelines as each site will have

different monitoring, sampling, and

treatment requirements.

Know the Difference Between Stormwater, Groundwater, and Surface Water

� STORMWATER: Accumulates in low spots after rain and snow storm events.

� GROUNDWATER: Water that is contained underground and rises to the surface when soil is disturbed.

� SURFACE WATER: Streams, rivers, and lakes. Otherwise known as Waters of the State.

Stormwater Dewatering Techniques

Image courtesy of CDOT.gov

Do not place dewatering bag in waterway Do not place dewatering bag in an inlet. A dewatering bag is required!

Image courtesy of udfcd.org Image Courtesy douglas.co.us

Place pump in bucket

with gravel pack

� A dewatering bag must be placed on the end of the hose.

� Place the bag on a flat surface with grass, straw bales, or a rock pad underneath. Do not place on bare soil.

Groundwater and surface

water dewatering are highly

regulated.

Refer to your State permit for

Specific requirements.

Image courtesy simonmoose.com

� Clear water diversions must divert the water

before the soil disturbance and discharge the

water after the soil disturbance.

Image Courtesy of megasecur.com

Image courtesy colonial-material.com