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Category 4e Assessments and Documentation

Category 4e Assessments and Documentation

A waterbody can be placed in category 4e (Ongoing Restoration Activities) if it’s impaired but recently completed or ongoing restoration activities are underway to restore the designated uses of the waterbody. For 4e plans, the waterbody is still included on the 303(d) list, but placement on the Verified List is postponed for one five-year assessment cycle, to allow for implementation of the 4e plan and evaluation of progress toward restoration. If at any time the department determines that reasonable assurance or reasonable progress are not being met, the Verified List will be amended accordingly. This indicates that where a 4e plan is approved, the decision to develop a TMDL is deferred until additional information is submitted to complete the pollutant reduction plan, or until additional water quality data are collected documenting that a waterbody is no longer impaired and consideration for Category 2e (Not Impaired - Ongoing Restoration Activities) is warranted.
The goal of a 4e plan is to implement appropriate restoration activities and, if necessary, additional study so that by the next assessment cycle either a 4b Reasonable Assurance Plan (RAP) can be approved or the waterbody attains water quality standards for the parameter causing the impairment. If the waterbody is still identified as impaired by the next assessment cycle and a 4b plan has not been approved, then the waterbody would likely be placed in Category 5 and included on the Verified List, unless there are additional and substantial restoration efforts scheduled that justify keeping the waterbody in Category 4e for another assessment cycle.
There are a number of benefits to implementing such a plan. First, plan development is locally controlled. Second, an approved plan postpones the development of a TMDL for the impairment by moving straight to restoration activities. Finally, a Category 4e plan enables stakeholders to focus on implementing projects and fixing problems, not on the TMDL process itself. A 4e plan is somewhat more flexible than a 4b RAP but it should describe the goal of the plan (e.g., a 4b RAP will be completed prior to the next assessment cycle and reasonable progress toward restoration will be achieved in the interim, stormwater treatment upgrades have recently been completed that should address the identified impairment by the next assessment cycle, etc.). Example 4e plans and their supporting documentation can be found here

Water Quality Restoration Plan Progress (Category 4e)

4e Process Step Description

Plan Initiated

  • Entities have contacted the department expressing interest to pursue a 4e plan
  • Entities have identified recently completed or ongoing restoration activities are underway to restore impaired waterbody
  • Participating partnering entities (public/private) have been identified 

Develop Restoration Plan

  • Waterbody/watershed has been identified
  • Current (impaired) conditions have been described
  • Area of effort has been identified 
  • Responsible participating entities have been identified
  • Goal of the plan has been stated
  • Interim water quality–based targets have been determined for the waterbody
  • An estimated target date for water quality criteria to be attained has been determined
  • Point and non-point source pollutants have been identified
  • Projects have been identified to provide the reasonable assurance that the proposed management actions can achieve the designated uses of the waterbody
  • Commitment to take additional actions if the planned activities do not completely redress the impairment have been provided
  • Assurance of confirmed sources of funding has been provided
  • Procedures for monitoring, compliance assessment and reporting have been identified
  • Key indicators that will be assessed to provide assurance of progress in the right direction are included
  • An implementation timeframe for the plan has been established

Finalize Restoration Plan

  • Plan has been presented to the department
  • Supporting documentation has been provided to the department

Finalize Assessment

  • Plan has been approved by the department  

Implement Restoration Plan

  • Projects (structural and non-structural) are moving forward and being implemented
  • Monitoring is continuing

Evaluate Progress

  • Reports are submitted, including updates on planned projects, monitoring results, changes to restoration project schedule, etc.
  • Information has been submitted to complete the pollution reduction plan
  • Water quality monitoring data have been collected to document that the waterbody is no longer impaired

Progress Demonstrated

  • Project implementation is verified
  • Project implementation has resulted in load reductions
  • Improvements in water quality are observed
Last Modified:
February 12, 2024 - 1:41pm

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