2018-03-26-minutes-public-works-study-session

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Fact Sheet 2.1— Who's Covered? Designation and Waivers of Regulated Small M54s Page 3 ® Potential Designation by the NPDES Permitting Authority — Physically Interconnected Under the final rule, the NPDES permitting authority was required to designate any small MS4 located outside of a UA that contributes substantially to the pollutant loadings of a physically interconnected MS4 regulated by the NPDES stormwater program. The final rule did not set a deadline for designation of small MS4s meeting this criterion. Physically interconnected means that one MS4 is connected to a second MS4 in such a way that it allows for direct discharges into the second system. State and EPA permitting authorities can be contacted to obtain a full list of regulated MS4s, including both the automatically designated MS4s and those that were additionally designated. Are Waivers from the Phase II Permit/Program Requirements Possible? es, two waiver options are available to operators of automatically designated small MS4s if discharges do not cause, or have the potential to cause, water quality impairment. The first applies where: (1) the jurisdiction served by the system is less than 1,000 people within the urbanized area; (2) the system is not contributing substantially to the pollutant loadings of a physically interconnected regulated MS4; and (3) if the small MS4 discharges any pollutants identified as a cause of impairment of any water body to which it discharges, stormwater controls are not needed based on wasteload allocations that are part of an EPA approved or established "total maximum daily load" (TMDL) that addresses the pollutant(s) of concern. TMDLs are water quality assessments that determine the source or sources of pollutants of concern for a particular waterbody, consider the maximum amount of pollutants the waterbody can assimilate, and then allocate to each source a set level of pollutants that it is allowed to discharge (i.e., a "wasteload allocation"). Small MS4s that are not given a wasteload allocation would meet the third criterion above. The second applies where: (1) the jurisdiction served by the system is less than 10,000 people; (2) an evaluation of all waters of the U.S. that receive a discharge from the system shows that stormwater controls are not needed based on wasteload allocations that are part of an EPA approved or established TMDh that addresses the pollutant(s) of concern or an equivalent analysis; and (3) it is determined that future discharges from the small MS4 do not have the potential to result in exceedances of water quality standards. The NPDES permitting authority is required to periodically review any waivers granted to MS4 operators to determine whether any information required for granting the waiver has changed. Minimally, such a review needs to be conducted once every five years. Can More than One MS4 in the Same Political Jurisdiction Be Automatically Designated? Yes. Since the final rule provides automatic coverage of all small MS4s within a UA, the result would likely be coverage of several governments and agencies with multiple, perhaps overlapping, jurisdictions. For example, a city that is located within a UA and operates its own small MS4 could be designated alongside the State's department of transportation (DOT) and the county's DOT if the State and county operate roads that are within the borders of the city. All three entities would be responsible for developing a stormwater management program for the portion of their respective MS4s within the city limits. In such a case, the permittees are strongly encouraged to work together to form a unified stormwater management program. Who Is Responsible if the Small MS4 Operator Lacks the Necessary Legal Authority? Some regulated small MS4s may lack the necessary legal authority to implement one or more of the required minimum control measures that comprise the Phase II stormwater management program. For example, a local government that is a small MS4 operator may be in a State that does not have an enabling statute that allows local regulatory control of construction site runoff into the sewer system. Another example is a State DOT that may not have the legal authority to require and enforce controls on illicit discharges into its system. In these situations the small MS4 is encouraged to work with the neighboring regulated small MS4s. As co -permittees, they could form a shared stormwater management program in which each permittee is responsible for activities that are within their individual legal authorities and abilities.