Long before PA DEP implemented its Municipal Separate Storm Sewer Systems (MS4) Program, ARRO assisted its municipal clients in addressing their stormwater problems. ARRO has always taken a holistic approach to stormwater management in an effort to mimic the pre-disturbance hydrologic conditions. Local drainage patterns, soils, geology and vegetation land cover play an important role in the development of any successful stormwater project. ARRO has a proven history of developing innovative new development and remedial stormwater designs, best management practices (BMPs) and retrofit strategies, green infrastructure, as well as floodplain and stream restoration projects. In addition to stormwater management design, ARRO is well-versed in floodplain and stormwater ordinance development, implementation, and enforcement.

ARRO is also a leader in MS4 compliance, providing MS4 consulting services for municipal clients across seven counties and two states. MS4 consulting services include the following:

  • MS4 Notice of Intent applications
  • Annual MS4 compliance reports
  • Minimum Control Measure (MCM) Program development and compliance
    • MCM 1- Public Education and Outreach on Stormwater Impacts
    • MCM 2 – Public Involvement/Participation
    • MCM 3 – Illicit Discharge, Detection and Elimination (IDD&E)
    • MCM 4 – Construction Site Stormwater Runoff Control
    • MCM 5 – Post-Construction Stormwater Management (PCSM)
    • MCM 6 – Pollution Prevention/Good Housekeeping
  • MS4 map development
  • Stormwater structure inventories
  • Annual outfall inspections and reporting
  • Illicit discharge inspections and reporting
  • Onsite training for staff and municipal officials
  • Compliance report monitoring
  • Public meeting development and oversight
  • Preparation and implementation of Pollution Reduction Plans to satisfy Appendix B, C, D, and E of the PA DEP Municipal Requirements Table
  • Preparation and implementation of TMDL compliance plans and Chesapeake Bay Pollution Reduction Plans

Implementation of the MS4 Program has dramatically changed over the last several years. A municipality can no longer assume it is compliant without having established a long-term program goal and multiple short-term objectives to achieve that goal. Implementation of the six Minimum Control Measures, as outlined in the MS4 Permit, provides the outline for how the MS4 Program is developed; however, the Minimum Control Measures content needs to be location specific and address localized issues.

ARRO can assist municipalities in defining MS4 Program objectives and goals and implementing procedures to maintain a compliant MS4 Program. ARRO has participated in and successfully navigated our clients through EPA MS4 Program audits and PA DEP MS4 Program reviews. These experiences, coupled with our in-depth understanding of the MS4 Permit requirements, allow ARRO to develop and oversee multiple successful MS4 Programs and provide technical oversight to municipalities that wish to manage the program themselves.

ARRO’s approach to support compliance and fulfill permit requirements includes:

  • The submission of the Notice of Intent (NOI) to the DEP within 180 days of the permits effective date.
  • We perform watershed assessments and assist in developing action plans for stormwater waste load allocations (WLAs). Our plans provide a schedule for implementing best management practices (BMPs) to reduce pollution and meet water quality standards.
  • We assist in developing the required six Minimum Control Measures (MCMs).