Top 7 Common Stormwater Inspection Mistakes And What To Do

Top 7 Common Stormwater Inspection Mistakes And What To Do

By law, many states require weekly, monthly, quarterly, and sometimes annual stormwater inspections to ensure proper compliance within the guidelines set by that particular state’s Construction General Permit.

An approved Stormwater Pollution Prevention Plan (SWPPP) should include regular inspections of all best management practices (BMPs) to ensure legal compliance and erosion/sediment control.

Construction managers and businesses should prioritize regular inspections and maintenance to avoid costly issues down the road. Not only does this make your work zones and buildings safer, but it also protects the public against any possible pollution or flooding.

However, due to the complexity of stormwater management and the disarray of work zones, stormwater management mistakes are common.

Here is a checklist of the top 7 mistakes found during stormwater inspections to keep you prepared, and what to do about each to ultimately save your company time and money.

1. Missing Sediment Controls

Most construction site managers focus on erosion control, and for a good reason. Erosion leads to sedimentation, which could be devastating in regards to Erosion Control and permit compliance within your limits of disturbance.

Unfortunately, many construction managers often ignore proper sediment control because they either view it as a secondary measure or don’t take the proper precautions to guard against sediment.

As sediment overpowers broken inlets and enters infiltration basin beds, sediment turns to silt, speeding up the erosion process and rendering the basin inoperable.

To help prevent sediment buildup, proper functioning inlets should be installed or maintained to filter out debris before entering basins. In addition, inspect existing yard inlets and pipe discharge points around the basin for any cracks to identify areas that need repair.

Installing proper covers or protection around inlets will help reduce sentiment buildup.

A properly functioning sediment basin bed can filter out up to 80% of total sediment particulates by some estimates.

Therefore, for permanent stormwater management basins, proper sediment disposal and infiltration BMPs are critical to maintaining legal compliance and preventing costly issues like flooding.

2. Poor Grading Plan

Positive grading directs stormwater runoff away from the foundation of a property and toward a proper outlet point. Conversely, wet areas after storms, exposed root vegetation, and even insect infiltrations can be red flags that your property has poor stormwater grading.

Unfortunately, many construction managers, in an effort to save time, either ignore or don’t implement proper grading procedures or protection around active work zones.

For this reason, it’s wise to implement proper barriers around work zones and improve grading procedures with the help of a contractor to ensure that your property is adequately protected.

3. Vegetation Mismanagement

Proper vegetation management is critical to reducing the ill effects of stormwater runoff. First, foliage helps block stormwater runoff and filter out sediment. Secondly, foliage and trees also increase soil infiltration and its absorption of stormwater runoff.

Uniform vegetative and grass growth is a good sign of proper stormwater management. However, many residential areas, abandoned work zones, and even active work zones suffer from poor vegetation management. One sign to look for is whether or not perineal foliage comprises around 70-75 percent of its previous density from the year before.

Unfortunately, you will leave your stormwater basins and management structures vulnerable to sediment and erosion without proper vegetation management.

With that said, creating an SWPPP plan with a focus on rejuvenating the growth of perineal and non-invasive foliage species around stormwater sites will help you avoid these issues in the future.

In addition, temporarily treating disturbed vegetation zones during construction is also important. Most states require temporary stabilization of disturbed areas that remain idle after work. As a general rule of thumb, we recommend using straw or mulch for an area that will remain idle for around three weeks and temporary seeding for areas undisturbed for more than a month.

4. Sediment Spilling on Roads

Sediment from stormwater runoff and washout can easily leak out onto roads and sidewalks from active work zones without proper management. This runoff is by far one of the most common violations caught during the inspection.

Fortunately, actively managing this problem by monitoring sweeping schedules and storing hazardous materials will help prevent these violations.

In addition, erecting barriers to catch sediment before they leak onto roadways will help keep your worksite up to code. As a bonus, these measures will also help cut down on inlet maintenance and sediment buildup near BMPs.

5. Damaged Outlets

Stormwater outlets help control the velocity of stormwater discharge after a storm.  This is the last line of defense before stormwater leaves the site.

Unfortunately, outlet BMPs often get ignored simply because they are out of sight and out of mind.

That’s why managers must conduct routine inspections to inspect outlet structures for any signs of cracking or erosion, especially before and after rain events occur. Failing to address outlet issues properly could result in pollution or significant damage to the overall structure.

To improve the dewatering process of stormwater, inlets and outlets should be situated to maximize the distance of travel between the two. In addition, strategic vegetation and rock walls should be set up around outlets to reduce their exposure to erosion.

Using rocks to regrade and repair broken outlets is recommended to repair any damaged outlets.

6. Poor Waste Disposal Practices

Proper waste disposal of solid objects like oil, cement, paint, and trash are essential considerations that construction managers must also address in their SWPPP.

Proper storage and recycling of these materials will come up in the inspection and are often a source of fines and other negative consequences due to the cluttered nature of worksites.

In addition, washouts from concrete, oils, and other toxic materials should be securely stored, clearly marked, and recycled to avoid mixing washout water with stormwater runoff. Failing to follow these practices or incorporating them into your SWPPP can cause you to fail your inspection and lead to possible stormwater pollution.

7. Improper or Outdated BMPs

Finally, a significant source of failed inspections is outdated or improper best management practices.

The EPA divides BMPs into two categories:

  • Structural (Silt Fences, Functional Inlets, Concrete Washouts, Check Dams, Ponds, Outlets, Outlet Control Structures)
  • Vegetative (Sodding, Mulch and Straw, Erosion Slope Matting, Temporary Seeding)

By studying and implementing BMPs into your work zone or business, you can adequately grade, seed, and protect your structures from stormwater runoff and infiltration basins to prevent erosion and sediment.

Including these BMPs into your SWPPP is the first step toward combating any issues found on your inspection and training staff on best practices.

With these BMPs in place, you will ensure that you never fail an inspection again and that you maintain proper maintenance of your stormwater management plan.