NPDES Construction Site Inspection Best Practices

This Inspection Guide describes how to conduct stormwater inspections on construction sites and discusses inspector responsibilities, preparation, inspection procedures, report writing, tips on inspecting BMPs, and enforcement.

An on-site construction site inspection will typically consist of the following components:

  • Pre-Inspection Preparation
  • Entry
  • Records Review
  • Site Inspection
  • Inspection Report Preparation

Pre-Inspection Preparation

In preparing for an inspection, you should review available files such as permits, copies of SWPPPs or erosion and sediment control plans, past inspection reports, downstream water quality problems from monitoring/assessment reports, and other correspondence such as maintenance records on the construction sites you will be inspecting. Also take into account sites that discharges to impaired waters as they will have additional requirements that are described in the NPDES permit. Be prepared for the inspection. Dress for the weather and make sure to have the appropriate safety gear/PPE.

Entry

Before entering the construction site, observe the surroundings and the various stages of construction. Note areas for in-depth review and any clear violations. This is also a good time to view construction site vehicle exit locations and perimeter controls. Indicate on the inspection form the date/time and weather conditions (e.g., light rain, sunny, some rain in previous 24 hours).

When entering the site, it is always good practice to locate and ask to speak with the site representative (superintendent, foreman, project manager, etc.) or someone who is familiar with the construction site. Always note the names of the individuals with whom you meet and speak to.

Records Review

During the records review, make sure that all of the required records are on site:

  • Copy of the NPDES Notice of Intent and proof of submittal
  • Copy of the approved erosion and sediment control plans
  • Copies of the past inspection reports (weekly and post rain event)
  • Copies of the stormwater sampling reports (if required) and proof of submittal
  • Copies of any self-reported violations

If these records are not available, ask why and note the response in your report. There are no legitimate excuses for not having stormwater paperwork on-site and available for review. Inform the contractor that the permit requires these records to be on-site or readily available for review.

Site Inspection

A keen eye, an understanding of the construction sequencing process and accurate documentation are the keys to an effective construction site inspection. Use the inspection form, and take notes regarding the location and condition of BMPs, discharge points, and inlets.

Review the sitemap and plan how you will conduct the inspection (this is particularly important for large construction sites). Identify the significant pollutant sources and BMPs you want to inspect (silt fence installation, sediment basins, slope stabilization, material storage areas, etc.). Consider the direction stormwater will flow as you plan the inspection. Begin your inspection at the low point on the construction site, observing all discharge points and walk up the slope to inspect the rest of the site. Consider the current sequence of construction phasing when planning your inspection.

Inspect discharge points and downstream, off-site areas for signs of impact. When inspecting discharge points from the site, if it appears that sediment is leaving the site, walk downstream to document the extent of travel and impact on receiving waters or storm drain systems. Note on the inspection form all environmental impacts and document with photographs if needed. If needed or required, collect samples of stormwater discharges from a construction site at the locations specified in the erosion control plan.

Inspect perimeter controls. Note the type of perimeter controls installed at the site, and whether these have been properly installed and maintained. Note if any perimeter controls need to be replaced. Inspect the construction exit to determine if there is excessive tracking of sediment from the site. Is there evidence of additional construction exits being used that are not in the plan or are not stabilized? Check all sediment controls. All storm drains must be protected and temporary stockpiles must have sediment controls installed.

Compare BMPs in the plans with construction site conditions. Are all BMPs required by the plans in place for the current phase of construction? Are additional BMPs needed? Evaluate whether BMPs have been adequately installed and maintained. Describe in your notes the potential violations and their location. Look for areas where BMPs are needed but are missing and are not included in the plans.

Inspect disturbed areas not currently being worked. All exposed soil areas must have temporary stabilization initiated whenever any construction activity has ceased on any portion of the site and will not resume for a period exceeding 14 calendar days. Note any areas that may require temporary stabilization.

Inspection Report Preparation

Make sure all observations and deficiencies are recorded on the inspection report. Also, note any maintenance that was performed since last inspection. Debrief the person in charge. Explain the results of the inspection and answer any questions and concerns. Explain the identified deficiencies and any areas of concern (reports are missing, inspections are not being done, silt fence was down, sediment leaving the site, etc.). Lastly, if it appears additional BMP’s may be needed, don’t tell the contractor which BMP to use. Explain the problem or the permit requirement that must be met, and describe how other construction sites have addressed typical problems. It’s OK to tell the contractor about what typically works and what doesn’t work in the field, but don’t specify the BMP to use (especially if it is a proprietary BMP). Ultimately, it is up to the contractor to decide which BMPs to use. If the contractor is not sure, recommend that the design professional on record be contacted to revise the erosion control plan.

Common compliance problems at construction sites

  • No temporary or permanent cover where needed or required. All exposed soil areas must be stabilized no later than 14 days after the construction activity in that portion of the site has temporarily or permanently ceased. Ask the contractor when particular exposed slopes were last worked to help you determine if there is compliance.
  • No sediment controls on site. The NPDES permit requires sediment control practices (e.g., sediment traps/basins, silt fences or sediment barriers, check dams, etc.) installed before land disturbing activities begin.
  • No inlet protection. All storm drain inlets that receive a discharge from the construction site must be protected before construction begins, and must be maintained until the site is stabilized. Inlet protection may be removed for a particular inlet if a specific safety concern has been identified.
  • No BMPs to minimize vehicle tracking on public right of way. Vehicle exits must use BMPs such as stone pads, concrete or steel wash racks, or equivalent systems to prevent vehicle tracking of sediment or mud off-site.
  • Sediment on the road. If BMPs are not adequately keeping sediment off the street, then the permit requires tracked sediment to be removed (e.g., street sweeping).
  • Improper solid waste or hazardous materials management. Solid waste must be disposed of properly, and hazardous materials (including oil, gasoline, and paint) must be properly stored (which includes secondary containment).
  • Concrete washout. All liquid and solid wastes generated by concrete washout operations must be contained in a leak-proof containment facility or impermeable liner. Area must have a sign.

For decades, HB NEXT has been serving construction firms in the areas of stormwater compliance. Contact HB NEXT for SWPPP / NPDES inspections at your next jobsite.

 

 

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