Briefing on Proposed Regulations for Discharge of Groundwater to MS4

DOEE is seeking informal comments from the regulated community on the Discharge of Groundwater to the Municipal Separate Stormwater Sewer system (MS4) draft regulations.

The proposed regulations, which create a permit-by-rule, will establish a predictable process to approve groundwater discharge into the District’s municipal separate stormwater sewer system (MS4). The proposed regulations will also ensure that the health and use of receiving waterbodies are adequately protected, consistent with the federally required water quality standards for those waterbodies.

The proposed process addresses key concerns that DOEE has heard from the regulated development community, including:

• Providing flexible options for characterizing proposed discharges;
• Establishing clear requirements for what is necessary to obtain and maintain discharge authorization;
• Focusing monitoring requirements on specific pollutants of concern at a site, rather than every possible pollutant;
• Providing certainty about the types of analytical methods that are acceptable for characterization and monitoring; and
• Creating a data-based pathway to reduce ongoing monitoring requirements at eligible sites.

Additional description of each of the bulleted items is provided below, as well as an explanation of the fee structure for application reviews that DOEE is proposing.

Flexible options for characterizing proposed discharge. The proposed regulations make several changes from the current process to reduce the burden on applicants and provide additional flexibility for characterizing the proposed discharge.  For example, an applicant can submit an initial discharge characterization report that consists of at least one of the following:

• A Phase I report that does not identify sources of contamination;
• A Phase I report that identifies sources of contamination and a Phase II report that includes chemical analysis of the proposed discharge for pollutants associated with the contamination;
• A Phase I report that identifies sources of contamination and a chemical analysis of the proposed discharge for pollutants associated with the contamination; or
• Chemical analysis of water samples that represent the proposed discharge for a range of pollutants not specific to any one type of contamination.

Establishing clear requirements for discharge authorization. The proposed regulations establish the number of characterization samples required to characterize discharge. They establish the standard against which these samples will be judged.  They also establish the frequency of monitoring that will be required after authorization is obtained and for how long that monitoring is required.

Focusing monitoring on specific pollutants of concern. After receiving discharge authorization, sites with known or suspected contamination will be asked to monitor for specific pollutants associated with that type of contamination, as well as the fuel and solvent pollutants that are widespread in the District and prone to being drawn into discharge at otherwise uncontaminated sites. This is a more targeted approach than requiring testing for the entire list of parameters associated with the District’s water quality standards.

Certainty about analytical methods. The proposed regulations specify the analytical methods that DOEE will accept for characterization of groundwater and for monitoring discharges.

Reducing monitoring at eligible sites. The proposed regulations establish a pathway by which permittees may request to reduce monitoring frequency and cease monitoring for certain pollutants after a specified number of sampling events. The Department may approve a reduction in frequency based on pollutant levels complying with permit limits for consecutive sampling events. They may allow a permittee to cease monitoring of a specific pollutant based on pollutant levels being reported as non-detects for consecutive sampling events.

Proposed fee structure. DOEE’s establishment of a Dewatering Approval Program is predicated on its ability to track and demonstrate that permitted discharges comply with the MS4 Permit issued to the District by EPA Region 3. To do this and provide predictable, timely, and user-friendly service to applicants and participants in the dewatering program, DOEE is proposing a fee structure that will allow it to recover its costs. These costs include staff dedicated to the review of submittals, inspection of sites, and evaluation of monitoring reports. Costs also include the development of an online database that will systematize and streamline the application, review, and approval process, as well as the submittal and evaluation of monitoring reports. DOEE expects to provide an on-line system for dewatering that is very similar to the Stormwater Database (SWDB) that DOEE developed to support the implementation of the stormwater management regulations. The SWDB enabled DOEE to implement numerous business process improvements and track its own performance, as well as report to EPA on project compliance with the MS4 Permit.  DOEE envisions similar enhancements to customer service and tracking for the dewatering program.

The proposed fee structure includes different rates depending on whether an applicant’s site has contaminated groundwater and if it is a residential site with less than 10 units. The differences in fees are meant to strike a balance between being able to cover the actual cost to DOEE to review, inspect, and monitor the discharge from different sites for the length (valid for five years) of the authorization, and being equitable.  The structure ensures that owners of small residential sites are not paying fees that are disproportionately burdensome compared to sites with large commercial or residential buildings. The structure also ensures that owners with uncontaminated groundwater will not have the same financial burden as sites that have contaminated groundwater, even though there still is a cost for sites with uncontaminated groundwater to review the application and monitor results over the life of the authorization.

Comparison of proposed fees associated with approving a discharge of groundwater to MS4 relative to a temporary discharge authorization (TDA) of groundwater to the sewer. To get a MS4 discharge approval for groundwater that has known or suspected contamination, applicants must pay an initial fee ($1,000) and a final fee ($12,000). That is a total of $13,000 for a five-year authorization for a commercial site or residential site with 10 or more units and where there is contamination known or suspected. In comparison, to discharge groundwater from a site to the sanitary sewer, DC Water does not charge an application fee, but does charge based on a metered flow. The cost to discharge groundwater to the sewer is $3.11 per 1,000 gallons (fiscal year 2018). This equates to an annual charge of about $150,000 for a construction site that discharges 100 gpm (this is a typical discharge rate for large construction projects) of groundwater to the sewer. DC Water issues TDAs for two-year periods.

DOEE requests that comments or questions on the proposed regulations be sent to Ed Dunne at Ed.Dunne@dc.gov.

You are encouraged to review the 35-page document prior to this briefing where the leaders from DOEE will share the highlights and answer questions/receive feedback.

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