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The second in our series of articles on how to effectively prepare for an EHS compliance audit, this article addresses the water audit. Companies typically use internal or external compliance audit teams to routinely conduct compliance audits to minimize the likelihood of non-compliance situations and possible enforcement action. Systematically preparing for an audit can facilitate the process and ensure a meaningful process. The complexity of a water audit can range from relatively simple to extremely involved and complex, depending on the type of facility, applicable programs, industry sector, and type of discharge(s).

In accordance with the Clean Water Act, a National Pollutant Discharge and Elimination System Permit (NPDES) is required for discharging pollutants from a point source into a water body of the United States. While there are a variety of water types referenced in the Act, this article focuses on stormwater and industrial wastewater from construction and industrial activity.

Most states are authorized to implement their own NPDES program. In addition to the federal rules, state and tribal regulations should be considered during the audit.

Stormwater-Only Discharge

The NPDES stormwater program regulates stormwater discharges from three potential sources: municipal separate storm sewer systems (MS4s), construction activities, and industrial activities. The audit will consist of a site inspection and desktop review of monitoring, recordkeeping and reporting (MRR) requirements.

Auditor's site inspection may review these components

Outdoor storage areas exposed to stormwate - Examples of outdoor storage may include oil and waste oil tanks, open waste containers such as those for metal shavings that may contain residual oil, or any chemical storage containers that have the potential to leak and cause harm to the environment. These areas will be inspected for obvious signs of contamination that would indicate there was a past release or ongoing concerns that may impact stormwater runoff. The auditor will review the existing Stormwater Pollution Prevention Plan (SWPPP) and/or site layout maps prior to the site visit to become familiar with the locations of the storage areas and point discharge locations. This will expedite the onsite review.

Covered storage facilities - If a facility stores the containers referenced previously in a covered storage facility that would prevent contact with stormwater, it may be eligible for a No Exposure Certificate. Each state manages this process differently; some may require an official certificate that includes some monitoring and recordkeeping. The site auditor will evaluate the covered storage and the integrity of the storage area to ensure that it meets the requirement for “No Exposure.” A copy of the certificate and site location maps will be reviewed prior to the site visit and audit.

Point discharge locations (outfalls) - Stormwater discharge locations can be a pipe that collects water from drains across the facility, and they could also include an area at the edge of the property line that collects overland flow water to a ditch or culvert. In many cases, erosion may have created an outfall location that is not known to the facility operator. The auditor will inspect the entire property line and identify each permitted outfall and make note of any areas of erosion, if warranted. It is ideal for the inspection to be completed during a rain event so that the auditor can visually screen the stormwater flow direction and determine if there is any sheen or other discoloration of the water discharging from the outfall. Site maps with the flow direction and outfall locations will be reviewed by the auditor prior to the site visit.

Inside and outside drains - The auditor will evaluate the drains both inside and outside of the facility. The direction and receiving pipes for the inside drains should be documented by the facility. Does the water drain to a wastewater treatment facility on-site? Does it drain to a stormwater pipe or a sump? Are the outside drains clear of debris, including rocks, dirt, leaves and any visual evidence of a sheen and/or other contamination?

Stormwater management facilities - Stormwater may be managed with on-site containment ponds and a levee to allow for overflow during a high storm event. The levee can also be used to contain a spill that may flow toward and into the pond. The auditor will visually evaluate the integrity of the system and review the detention calculations for the facility. During the interview process, the auditor may question facility personnel about historical flooding and flow direction observations.

Silt fences and sediment traps and basins - These examples of best management practices are used typically during construction to deter stormwater from carrying silt off-site to other properties and to nearby streams. Silt fences are used until the vegetation has been reestablished or in areas where it is difficult to grow vegetation. The auditor will evaluate the integrity of sediment traps and basins and check for sediment loading and debris.

Possible components of the Monitoring, Recordkeeping, and Reporting (MRR) Review

Stormwater Pollution Prevention Plan (SWPPP) - This plan is required by most state programs, but the required content varies by state. Content will be reviewed against the permit for the facility. A SWPPP plan typically requires an inventory of outdoor storage containers and equipment, identification of stormwater drains and outfalls, and best management practices (BMPs) for stormwater control. State permits often provide specific BMPs that should be implemented based on industry type. As noted above, a copy of the SWPPP should be reviewed by the auditor prior to the site visit in order to expedite the site inspection.

Discharge monitoring reports (DMRs) - DMR reports will be examined to evaluate the results of the analytical data collected. The auditor will review laboratory testing procedures, including sampling, sample management, holding times, and preservation, and general quality control. If there are exceedances to the limits listed in the permit, the auditor will investigate accordingly. Did you properly report the exceedance to the state? Did you resolve or identify the reason for the exceedance? Did you make changes to your SWPPP and implement new BMPs?

Reporting - Reporting requirements vary based on whether the permit is a general stormwater or individual permit. Reporting of the monitoring results can be required on a monthly, quarterly, and/or annual basis. Typically, there is an annual compliance report that must be submitted with a fee. The auditor will evaluate the conditions of the permit to determine if reporting has been properly submitted and documented.

Sediment and erosion control plans - If the permit was issued for a construction project, it will require a sediment and erosion control plan. This type of plan has a shorter term than a SWPPP and is followed until the construction is complete, the facility has established vegetation, and the BMPs are installed and properly managing stormwater. The conditions of the plan will be evaluated by the auditor. Some states and jurisdictions may require a sediment and erosion control plan as part of the SWPPP for non-construction sites as well, and this is usually incorporated into the SWPPP. Permits will be closely reviewed by the auditor for this determination.

NPDES federal or state inspection reports - Having inspection records readily available for review will help the auditor focus on sensitive areas identified by regulatory agencies. If there are noted violations in the inspection report, the auditor will request documentation indicating that the issue was resolved and will review the area of concern while on-site.

Training records - Training materials and records of training will be requested by the auditor. There are annual training requirements for facility personnel as specified in the permit. State requirements differ by state, with some being more stringent than others, and should be evaluated closely. Training requirements are specific to the site and usually provide guidance for personnel on collecting stormwater samples, conducting inspections, and reviewing the SWPPP.

Wastewater Discharge

Facilities that generate and discharge wastewater from their facilities must have an NPDES. This type of permit can cover both stormwater and wastewater, if applicable.

Additional site inspections and MRR aspects considered during a compliance audit

Sources of Wastewater - The auditor will evaluate whether all the sources of wastewater have been accurately identified and permitted. Water balance and process flow diagrams will be used in this determination. If the wastewater is mixed with stormwater, the auditor will evaluate the sample location.

Wastewater Treatment System - Wastewater treatment systems may require chemicals to be added to adjust the pH or chlorine levels, or to prevent scaling and microbial growth. These chemicals are approved by the agency during the permit application. The auditor will request a copy of the application and review the chemicals and the Safety Data Sheets (SDSs) for the chemicals being used, to determine whether there are any discrepancies.

Typically, the MRR requirements for a treatment system are more rigorous and may include daily pH, temperature, and flow requirements. These records will be reviewed by the auditor and compared to the permit effluent limits.

Disposal of Solid Waste Generated from System - Wastewater treatment systems may generate a solid waste (e.g., waste oil) that needs to be either further processed or disposed of by a third party. The auditor will review the disposal records and evaluate management of the waste material.

Zero-Discharge, Closed-Loop Systems: These types of systems are used to minimize the amount of waste generated by treating wastewater through recycling and then recovery and reuse for industrial purposes. As applicable, the auditor may want to inspect water balance calculations, land application requirements (e.g., for recycled water used for dust control), etc.

Audit Preparedness

A more effective audit preparation process will translate into a more efficient audit, since auditors will be able to devote more time to audit-specific tasks, rather than being immersed in solving audit logistic issues.

Trinity can help with providing site-specific guidance in preparation for an audit and with conducting EHS compliance audits for the following programs:

  • Air Quality
  • Water
  • Solid and Hazardous Wastes
  • Emergency Planning and Preparedness
  • Risk Management Plans and Accidental Releases
  • Coast Guard Facility Security Plans
  • DHS CFATS Regulations
  • Process Safety Management
  • Health and Safety Standards, including OSHA's General Industry Standards

For more information, please contact Trinity at (800) 229-6655 or complete the Contact Us form on our website.