Modernization of Stormwater Quality Rules.

• Author: Martin, Susan Roeder
• Position: Florida

In 2020, the Florida Legislature passed Senate Bill 712, the Clean Waterways Act, (1) requiring the Department of Environmental Protection (DEP) and the state's five water management districts (2) (collectively "the agencies") to initiate rulemaking to update stormwater design and operation regulations. This legislation passed with unanimous, bipartisan support and carries a wide range ofwater-quality protection provisions aimed at minimizing the impact of known sources of nutrient pollution and strengthening regulatory require-ments (3) The bill requires the agencies to revise the environmental resource permit (ERP) rules to include the most recent scientific information available, including low-impact designs, best management practices (BMPs), and design criteria that increase nutrient removal from stormwater discharges. The revised rules must also include measures for the consistent application of the net improvement performance standard to ensure significant pollutant loading reductions (4) from stormwater management systems. (5)

Background

Managing stormwater and its effects on surface and ground water is critically important to protecting Florida's water quality and the general environment. Stormwater management is especially important in urban areas because urbanization leads to soil compaction; alteration of natural landscapes, flood-plains, and wetlands; and the addition of pollutants from everyday human activities. Construction of impervious surfaces, including roads and parking lots, decreases the amount of rainwater that seeps into the soil to recharge aquifers, maintain lake and wetland water levels, and maintain spring and stream flows. Without proper management, the volume, speed, and pollutant load in stormwater that runs off developed areas increases, leading to flooding, water-quality problems, and loss of habitat. (6)

Florida has long recognized the importance of managing stormwater and was in fact the first state in the nation to adopt a rule requiring all new development treat stormwater to a specified pollutant load reduction level. (7) Storm-water rules were first adopted by the Environmental Regulation Commission in October 1981 and became effective in February 1982. (8) The rules included an 80% annual load reduction of total suspended solids as the stormwater treatment performance standard and included BMP design criteria. The rules also adopted a rebuttable presumption that discharges complying with the rules would not harm water resources.

DEP is the lead agency responsible for coordinating the statewide stormwater management program and is responsible for establishing goals, objectives, and guidance for development and implementation of the stormwater management program by water management districts and local governments. DEP delegated the implementation of the stormwater management program to the water management districts, which have implemented a comprehensive surface water management program under F.S. Ch. 373, Part IV. The water management districts are the chief administrators of the state stormwater management program within their geographic boundaries. Each water management district developed stormwater design criteria, modeled after the minimum design criteria outlined in F.A.C. Ch. 62-25 to achieve the minimum storm-water treatment standards specified in F.A.C. Ch. 62-40, the water resource implementation rule. (9)

F.S. Ch. 373, Part IV, provides the authority for the agencies to require a permit for the construction or alteration of a stormwater management system, dam, impoundment, reservoir, appurtenant work or works. F.A.C. Rule 62-330.010(2) states:

The ERP program governs the following: construction, alteration, operation, maintenance, repair, abandonment and removal of stormwater management systems, dams, impoundments, reservoirs, appurtenant works, and works (10) (including docks, piers, structures, dredging, and filling located in, on or over wetlands or other surface waters, as defined and delineated in chapter 62-340, F.A.C.)....

The three main criteria the ERP rules provide to protect the state's water resources are 1) water quality criteria to ensure compliance with state water quality standards; 2) water quantity criteria to prevent adverse flooding and maintain drainage; and 3) environmental criteria for the protection of wetlands and other surface waters, and the preservation and protection of habitat for fish and wildlife. (11)

Most current substantive ERP water quality and quantity rules are based on rules originally developed in the 1980s. This continuity of regulation has benefited stakeholders by providing consistency and certainty in permitting. However, the disadvantage to the state's water resources is that the rules are not based on the current state of scientific and engineering knowledge.

The Florida...