According to one estimate, construction-related activities were responsible for 40% of all water pollution in the United States.
This pollution can take many forms, from dangerous chemicals that leak out of work zones to increased turbidity from sediment and soil erosion.
Stormwater runoff is a major concern for construction sites as rainwater can carry away with it dangerous pollutants and chemicals that threaten local ecosystems. Likewise, improper stormwater management can lead to flooding and erosion of the local land.
While many site managers understand the importance of developing a stormwater management plan and active controls, they often overlook an important component of this plan: the stormwater inspection.
What Is a Stormwater Inspection?
A stormwater inspection is a legal requirement of a stormwater pollution prevention plan (SWPPP), which is typically required by government agencies if you plan to discharge stormwater runoff into a point source public water system.
Stormwater inspections assess the condition of a worksite and all active stormwater management prevention measures to ensure they work as intended. Inspections are typically conducted on a regular basis (every 7-14 days) or after a major rainfall event to ensure that all active controls are operating correctly.
These inspections can help identify any potential sources of pollution and errors that could be compromising your stormwater mitigation efforts. All inspections will be documented and included in your SWPPP to be submitted to the proper authorities.
The Importance of Regular Stormwater Inspections
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) will require regular inspections of all best management practices (BMPs) to ensure legal compliance and erosion/sediment control.
On the practical side, 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.
Luckily, by spotting these issues early, site managers can correct their mistakes and avoid any potential liability.
7 Common Stormwater Inspection Mistakes
Stormwater management is a complicated and ongoing process that will require some trial-and-error and correction. Here are some of the most common stormwater management mistakes we typically find during inspections.
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 regard 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, existing yard inlets and pipe discharge points around the basin should be inspected for any cracks to identify areas that need repair.
Installing proper covers or protection around inlets will help reduce sentiment buildup.
According to some estimates, a properly functioning sediment basin bed can filter out up to 80% of total sediment particulates.
Therefore, proper sediment disposal and infiltration BMPs are critical for permanent stormwater management basins, as they ensure legal compliance and prevent costly issues like flooding.
2. Poor Grading Plan
Positive grading directs stormwater runoff away from a property’s foundation and toward a proper outlet point. Conversely, wet areas after storms, exposed root vegetation, and even insect infiltration can be red flags that your property has poor stormwater grading.
Unfortunately, in an effort to save time, many construction managers either ignore or don’t implement proper grading procedures or protection around active work zones.
For this reason, it’s wise to hire a contractor to implement proper barriers around work zones and improve grading procedures 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, without proper vegetation management, your stormwater basins and management structures will be vulnerable to sediment and erosion.
With that said, creating a 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 it leaks 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. They are 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 of outlet structures for signs of cracking or erosion, especially before and after rain events. Failure 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 or incorporate these practices into your SWPPP can cause you to fail your inspection and lead to possible stormwater pollution.
7. Improper or Outdated BMPs
Finally, outdated or improper best management practices (BMPs) are a significant source of failed inspections.
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 in your work zone or business, you can adequately grade, seed, and protect your structures from stormwater runoff and infiltration basins, preventing erosion and sediment.
Including these BMPs in 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 your stormwater management plan is properly maintained and that you never fail an inspection again.
FAQs
Who needs a stormwater inspection?
Stormwater inspections are typically required for construction sites, industrial facilities, and commercial properties subject to a Stormwater Pollution Prevention Plan (SWPPP). Homeowners’ associations (HOAs) and municipalities may also need regular inspections.
How often should a stormwater inspection be conducted?
The frequency of stormwater inspections depends on regulatory requirements and site conditions. Construction sites often require weekly and post-rainfall inspections, while industrial and municipal sites may need quarterly or annual assessments.
What happens if a site fails a stormwater inspection?
If a site fails an inspection, the property owner or responsible party must take corrective action to fix the issues. This could include repairing erosion control measures, removing pollutants, or improving drainage. Non-compliance may result in fines or legal action.