Section 096-570-8 - Addition of new wastewaterA.When allowed. Unless the department determines that the nature or the volume of additional wastewater will adversely affect existing water quality of the receiving water, new sources of wastewater may be added to a sewer system having a CSO discharge point if: (1) The licensee is conducting a CSO Master Plan study on a schedule approved by the department;(2) The licensee is implementing the approved Master Plan; or(3) The licensee has completed implementation of the approved Master Plan.B.Review and documentation. In the cases of Section 8(A)(2) and Section 8(A)(3) above, the licensee must implement additional abatement measures, if necessary, to ensure that the additional wastewater will not exceed the targeted level of control or extend the implementation schedule in the approved Master Plan (see Section 3(B)(2)(b)(vi). In the case of Section 8(A)(1) above, the licensee must document practices, measures, or programs to mitigate impacts to the combined sewer system from the added wastewater. The licensee must consider, but is not limited to any combination of the following: (1) Implementation of the nine minimum controls as described in Section 5, above;(2) Removal of extraneous, uncontaminated water from private or public sources;(3) Physical improvements, alterations, or upgrades that result in reduced CSO activity;(4) Pollution prevention programs; or(5) Sewer separation projects.C. Submissions. Documentation of additions of wastewater to the combined sewer system, and associated mitigating measures must be included in the yearly CSO progress reports (see Section 7(H)). Reports must contain the volumes and characteristics of wastewater added or authorized for addition and descriptions of sewer system improvements and estimated effectiveness. NOTE: Stormwater runoff may contain various pollutants. Before separation projects are carried out, care should be taken to assure runoff borne pollutants are not simply redirected to the receiving water through another piping system. This is of particular concern in heavily developed areas where pollutant concentrations are likely to be higher. Licensees proposing sewer separation projects should investigate methods to control pollutants from the separated stormwater, such as the treatment and detention of stormwater through the use of stormwater Best Management Practices and reduction of stormwater runoff. Redirection of stormwater to areas supporting less sensitive uses or areas where fewer environmental impacts will result should also be considered.
06-096 C.M.R. ch. 570, § 8