Dewatering Discharge Permit Application
Allowable Discharges
The following are considered "allowable" discharges to the BWSC combined and storm drainage system:
- Diverted tide, river or stream flows
- Uncontaminated springs
- Flows from riparian habitats and wetlands
- Rising groundwater
- Uncontaminated groundwater infiltration to the drains
- Water main, hydrant flushing and other discharges from drinkable water sources associated with routine maintenance of the water distribution system
- Irrigation water
- Non-commercial car washing
- Swimming pool discharges which have been dechlorinated
- Street and pavement wash waters
- Discharges or flows from emergency firefighting activities
- Building washdown water which does not contain detergents
Any collected water discharged into a storm drain leading to a combined sewer system or into a combined sewer directly requires an MWRA Sewer Use Permit.
Discharges Requiring a Permit
Discharges to storm drains that require a Drainage Discharge Permit include, but are not limited to:
- Dewatering drainage
- Subsurface drainage
- Non-contact cooling water
- Non-contact industrial process waters
- Uncontaminated cooling water
- Uncontaminated industrial process water or waters associated with the excavation of a foundation or trench
- Hydrological testing
- Groundwater treatment/remediation
- Removal or installation of an underground storage tank
- Foundation drains, crawl space pumps or footing drains
Either an NPDES General Permit or NPDES Exclusion for the discharge must also be obtained and provided to BWSC. Drainage Discharge Permits may be revoked, suspended, or reissued if BWSC determines that the discharge is or may cause or contribute to a water quality problem or a violation of the BWSC's NPDES Permit. The duration of the permit shall not exceed the estimated dates of discharge.
It is necessary to research BWSC's wastewater maps to determine whether the discharge is to a sanitary sewer, combined sewer, or storm drain.