County of Niagara

An MS4 must, at a minimum:

a. Develop, implement, and enforce a program that:

i. provides equivalent protection to the NYS SPDES General Permit for Stormwater Discharges from Construction Activities (either GP-02-01, GP-0-08-001, or GP-0-10-001), unless more stringent requirements are contained in the MS4 General SPDES permit GP-0-10-002.

ii. addresses stormwater runoff from new development and redevelopment projects on or to County owned property from projects that result in a land disturbance of greater than or equal to one acre. Control of stormwater discharges from projects of less than one acre must be included in the program if:

• that project is part of a larger common plan of development or sale; or
• if controlling such activities in a particular watershed is required by the Department;
• iii. includes enforceable mechanisms for post-construction runoff control from new development and re-development projects to the extent allowable under State law that meet the State’s most current technical standards:
• through available mechanisms (i.e. tenant lease agreements, bid specifications, requests for proposals, standard contract provisions, connection permits, maintenance directives / BMPS, access permits, consultant agreements, internal policies);
• procedures or policies must be developed for implementation and enforcement of the mechanisms;
• a written directive from the person authorized to sign the NOI stating that updated mechanisms must be used and who (position(s)) is responsible for ensuring compliance with and enforcing the mechanisms for construction projects that occur on property owned by the covered entity or within the maintenance jurisdiction of the MS4; and
• the mechanisms and directive must assure compliance with the requirements of the NYS SPDES General Permit for Stormwater Discharges from Construction Activities;

iv. includes a combination of structural or non-structural management practices (according to standards defined in the most current version of the NYS Stormwater Management Design Manual) that will reduce the discharge of pollutants to the MEP. In the development of environmental plans such as watershed plans, open space preservation programs, local laws, and ordinances covered entities must incorporate principles of Low Impact Development (LID), Better Site Design (BSD) and other Green Infrastructure practices to the MEP. Covered entities must consider natural resource protection, impervious area reduction, maintaining natural hydrologic conditions in developments, buffers or set back distances for protection of environmentally sensitive areas such as streams, wetlands, and erodible soils in the development of environmental plans.

• If a stormwater management practice is designed and installed in accordance with the New York State Stormwater Management Design Manual or has been demonstrated to be equivalent and is properly operated and maintained, then MEP will be assumed to be met for postconstruction stormwater discharged by the practice;

v. establish and maintain an inventory of post construction stormwater management practices to include at a minimum practices discharging to the small MS4 that have been installed since March 10, 2003, those practices owned by the small MS4, and those found to cause water quality standard violations.

• the inventory shall include at a minimum: location of practice (street address or coordinates); type of practice; maintenance needed per the NYS Stormwater Management Design Manual, SWPPP or other provided documentation; and dates and type of maintenance performed; and

vii. ensures adequate long-term operation and maintenance of management practices by trained staff, including assessment to ensure practices are performing properly.

• The assessment shall include inspection items identified in the maintenance requirements (NYS Stormwater Management Design Manual, SWPPP, or other maintenance information) for the practice. Covered entities are not required to collect stormwater samples and perform specific chemical analysis;

viii. Covered entities may include the SWMP Plan provisions for development of a banking and credit system. MS4s must have an existing watershed plan based on which offsite alternative stormwater management in lieu of or in addition to on-site stormwater management practices are evaluated. Redevelopment projects must be evaluated for pollutant reduction greater than required treatment by the state standards. The individual project must be reviewed and approved by the Department. Use of a banking and credit system for new development is only acceptable in the impaired watersheds to achieve to no net increase requirement and watershed improvement strategy areas to achieve pollutant reductions in accordance with watershed plan load reduction goals. A banking and credit system must at minimum include:

• Ensure that offset exceeds a standards reduction by factor of at least 2
• Offset is implemented within the same watershed
• Proposed offset address the POC of the watershed
• Tracking system is established for the watershed
• Mitigation is applied for retrofit or redevelopment
• Offset project is completed prior to beginning of the proposed construction
• A legal mechanism is established to implement the banking and credit system

b. Develop, implement, and provide adequate resources for a program to inspect development and re-development sites by trained staff and to enforce and penalize violators;

c. Develop, record, annually assess and modify as needed measurable goals; and

d. Select appropriate post-construction stormwater BMPs and measurable goals to ensure the reduction of all POCs in stormwater discharges to the MEP.