Highlights: New permit requirements loom on the horizon as the Ohio EPA recently released two draft NPDES storm water general permits for public comment. The public comment period ended for each permit and, once the permits are final, there will be new requirements placed on construction activities and on municipal storm sewer systems. This article outlines the new requirements and compares these requirements with the already existing standards. Also discussed in this article are the penalties for failure to comply with the permits.

The Ohio EPA created the National Pollution Discharge Elimination System (“NPDES”) Stormwater Program after the 1987 amendments to the Clean Water Act. In general, the Ohio EPA created the program to reduce pollution from storm water discharges. As a part of the overall program, the general permits for construction activities and for Small Municipal Separate Storm Sewer Systems (“MS4s”) were developed.

On Dec. 24, 2007, the Ohio EPA released two draft NPDES storm water general permits for public comment. One permit, known as the Construction General Permit (“CGP”), allows storm water discharges associated with construction activities. The other permit allows storm water discharges from Small Municipal Separate Storm Sewer Systems (“MS4s”).

The comment periods for these permits ended on Feb. 14, 2008 and Feb. 21, 2008, respectively. Based on comments from the public, the Ohio EPA will consider whether further revisions to the draft permits are needed prior to making these permits final.

Who Will Be Covered?

The CGP applies to virtually all construction activities that disturb one or more acres of land. This applies to all types of construction projects whether they are schools, municipal buildings, treatment plants, private developments, etc.

The small MS4 general permit applies to all separate storm sewer systems owned or operated by a public body that has a population less than 100,000 within Draft NPDES Permits for Storm Water Discharges – The Impacts to Construction Activities and Small Municipal Storm Sewer Systems an urbanized area and many communities that are not within an urbanized area.

Potential Penalties

The penalty for not complying with the NPDES storm water permits can be high. By statute, the state is allowed to penalize a violator up to $10,000 per day. Since 2004, the Ohio EPA has penalized violators anywhere from $1,000 to $87,000 for non-compliance. These regulations are complex; school superintendents, city managers, and other public owners should make sure their design professionals are aware of these regulations and proceed accordingly.

There are many changes to the storm water NPDES general permits. Here, we will only focus on the changes that have a significant impact to construction activities and small MS4 communities.

Construction Activities NPDES Permit

The draft NPDES statewide general permit for storm water discharges associated with construction activities will be the first permit to become final. The CGP covers construction activities defined as clearing, grading, excavating, grubbing and/or filling that disturbs one or more acres. Revisions to this permit include the following four new or revised requirements.

1. Sedimentation Pond Sizes Will Increase

Under the current permit, a sedimentation pond is required for projects with concentrated storm water runoff, runoff that exceeds design capacity of silt fence and inlet protection, or runoff from “common drainage locations with 10 or more acres of disturbed land.” The minimum pond size under the current permit is 1,800 ft3/acre.

The draft permit makes significant changes to sedimentation pond requirements. The pond design requirements have changed to include specific requirements for a dewatering zone and sediment storage zone.

The permit requires a dewatering zone that must have a minimum size of 1,800 ft3/acre, the same volume per acre as the current permit requires for the entire basin. In addition, the dewatering zone must have a minimum 48-hour drain time if the drainage area is 5 acres or greater in order to meet the new requirements.

The draft CGP also establishes requirements for a storage basin’s sediment storage zone. The permit allows two methods for determining the size of the sediment storage zone. The first method is straightforward and allows for a set storage volume of 1,000 ft3/disturbed acre. The second method is more analytical. Using an acceptable erosion predication model, a designer can calculate the storage volume sufficient to meet sediment storage goals. Again, this storage volume is in addition to the storage volume required for the dewatering zone. In any event, the average size of sedimentation basins will increase under the draft permit.

2. Post-Construction BMP Requirements Are Changing

The draft CGP establishes new post-construction storm water management requirements to address the increase in quantity and quality of storm water runoff. These requirements center on the use of Best Management Practices (BMPs) to achieve NPDES goals.

The current permit specifies the requirements for “large construction activities”, i.e. construction activities that disturb five acres or more, or construction activities that disturb less than five acres but are part of a “larger common development or sale”. The Ohio EPA has removed this language from the draft permit. The draft permit language for post-construction requirements applies to all construction activities covered under the permit.

In addition, the draft CGP includes revisions to the available list of approved structural post-construction BMPs to provide options for both small drainage areas that are less than five acres and drainage areas five acres and larger.

The list of approved structural post-construction BMPs has been an issue for some construction activities. One issue of concern to public owners and contractors is the type of structural post-construction BMPs available for transportation projects. Because transportation projects are linear in nature, owners, engineers, and contractors have the daunting task of trying to find BMPs that are able to fit within the narrow project limits. The draft permit includes alternative structural post-construction BMPs that are suitable for linear construction projects and are intended to be just as effective as those BMPs approved for non-linear projects.

In the event there is no room to fit a structural BMP on-site, the Ohio EPA will review off-site structural post-construction BMPs on a case-by-case basis.

In addition to entertaining the idea of off-site structural post-construction BMPs, the draft permit allows for non-structural post-construction BMPs where maintaining the natural riparian and/or forested areas is deemed more beneficial to NPDES goals.

3. New Requirements to Protect Wetlands

By design, storm water drainage systems collect and discharge run-off at a discharge point. Some construction projects will have storm water outlets that drain directly to wetland areas. In this situation, the draft permit requires that the project owner prepare a wetland hydrologic analysis. The hydrologic analysis will be required to show that the post-construction storm water discharge will not negatively affect the hydrodynamics of the wetland.

4. Off-Season Inspection Frequency Reduced

Individuals responsible for inspecting construction sites have commented extensively on the current CGP off-season inspection requirements. Many of these individuals have commented that the frequency of inspection is too intensive.

Under the current permit, contractors have been required to inspect their project sites on a weekly basis during the winter months. Many contractors have not seen the need for this intensive inspection frequency where there is no active construction, disturbed areas are stabilized, and the ground is frozen. Under such conditions, the risk of runoff is very low.

In response to these concerns, the Ohio EPA has included a waiver for inspections where: (1) there is no land disturbance activities, (2) the ground will be frozen for at least a one month period, and (3) the waiver period is documented in the Storm Water Pollution Prevention Plan (SWPPP).

Small Municipal Separate Storm Sewer Systems NPDES Permit

Next, we will turn to the proposed changes to the NPDES general permit for small MS4s. Phase II storm water regulations have covered Small MS4s since 2003. Currently, the draft permit for MS4s consists of seven significant changes that will affect small MS4 communities.

1. Identification of the Responsible Parties

Because a storm water management program may involve many different parties from different organizations, there are many opportunities for an MS4 to lose track of who is responsible for program tasks. The draft small MS4 permit introduces a requirement to add an organizational table that will identify all parties responsible for the management and implementation of BMPs for each of the six minimum control measures. The purpose of this change is to provide an MS4 with the means of identifying the responsible parties and eliminate confusion that has occurred in the past.

2. Minimum Performance Standards

Currently, the existing storm water general permit requires that each individual MS4 establish its own performance standards for the Public Education and Outreach and Public Participation/Involvement components of its storm water program. The draft small MS4 permit now establishes the minimum performance standards small MS4 communities must meet.

Under the proposed draft permit, implementation of the Public Education and Outreach portion of the program will need to consist of more than one method of reaching the public and must target at least five different storm water topics over the permit period. Of these five storm water topics, a small MS4 community must direct one topic towards the development community. In addition, the draft permit will require that the Public Education and Outreach program reach at least 50 percent of the MS4’s population.

For the Public Participation/Involvement portion of the program, the draft permit requires that small MS4s hold at least five public participation activities over the permit term. MS4s will have two years from receiving permit renewal to comply with the new minimum performance standards.

3. Enhanced Mapping Requirements

The draft small MS4 permit also sets out new requirements for enhanced mapping of a community’s storm water system. The current permit requires small MS4 communities to map storm water outfalls and receiving waters as a part of the storm water management plan (SWMP).

The draft small MS4 permit will require that communities map all public as well as private storm water infrastructure. This requirement will include locating, identifying, and mapping each catch basin, storm sewer line, ditch, etc. The philosophy behind the new mapping requirement is to assist communities in managing their storm sewer system through identifying and tracking assets. If enacted as is, the draft permit will provide small MS4s five years to comply with the new mapping requirements.

4. Illicit Discharge Guidance

The draft permit provides additional guidance on how to deal with illicit discharges from home sewage treatment systems. Most communities have homes that are not connected to the public sanitary sewer system. Instead, discharges from these systems find their way into a community’s storm sewer system. Because of the direct discharge into the storm sewer system, home sewage treatment systems have become a source of pollution that the Ohio EPA categorizes as an illicit discharge. The current permit requires small MS4s to map the locations of these systems; however, the permit does not provide guidance on what to do with these systems after they have been located and mapped as illicit discharges.

To increase the likelihood of locating home sewage treatment systems, the draft small MS4 permit includes new performance standards for detecting illicit discharges. The draft permit requires that MS4s perform dry-weather screening of outfalls. By performing dry weather screenings, MS4s will be able to detect illicit discharges more easily.

To provide guidance on dealing with home treatment sewage systems the draft small MS4 permit provides minimum standards on how to deal with illicit discharges. The draft small MS4 permit requires that home sewage treatment systems that discharge into the storm sewer system and are within 200 feet of a public sanitary sewer be connected to the public sanitary sewer system. The draft permit also requires that small MS4s work with their local board of health to ensure that these systems are inspected appropriately.

Systems that are defective must be repaired or replaced. In addition, the small MS4 must evaluate the feasibility of extending sanitary sewers to areas within the MS4 that have been identified as having many home sewage treatment systems discharging to the storm sewer system.

5. Construction and Post Construction Ordinances

Under the draft NPDES permit, small MS4s will be required to develop local ordinances or other regulatory mechanisms that adopt construction and post-construction regulations associated with the MS4’s applicable CGP. At a minimum, these ordinances must be as strict as the CGP and in no way conflict with CGP requirements.

6. Storm Water Pollution Prevention Plans for Some Municipal Facilities

Under the current storm water NPDES permit, private facilities that meet the definition of industrial are required to apply for NPDES coverage. This has not been the case for public facilities that meet the same definition. Such facilities were not required to apply for NPDES coverage in the past, and according to the draft permit, such facilities are still not required to apply for coverage.

Under the draft permit, public facilities defined as industrial may be required to submit a storm water pollution prevention plan (SWPPP). If the Ohio EPA approves the draft permit as written, MS4s that obtain a permit renewal will have one year to prepare a SWPPP for each affected facility.

7. Standardized Annual Reporting

In order to provide more guidance on what type of information a MS4 community must submit in the annual report, the Ohio EPA has created a standard form that MS4s must use. Tracking the progress of a small MS4 community’s storm water program is not new. These communities are required to submit annual reports under the current permit.

What the Ohio EPA is attempting to do is to make the requirements easier to understand by standardizing the format. The Ohio EPA will allow an MS4 to submit its report in a different format; however, that MS4 must obtain permission from the Ohio EPA to use the requested format.

For more information on the draft NPDES general permits for storm water discharges and the Ohio EPA’s Storm Water Program, visit the Ohio EPA’s Storm Water Program website at http://www.epa.state.oh.us/dsw/storm/index.html.