Effluent Limit Guideline (ELG)

Effective February 2010, the EPA has passed the new storm water sampling requirements related to new construction. Prior to this ruling, only the industrial industry was required to collect storm water samples or states with specific ELG requirements in their construction general permits. Now that the ruling has passed, it is clear that every state will be required to implement these requirements into their permit during the next permit writing. By 2015 all ELG requirements will be enforced and implemented across the U.S. Thus, forcing the entire construction industry to comply with these regulations.

What are we sampling for?

Turbidity is our culprit. Turbidity is the ability of light to pass through a water sample. Particles, TSS and pollutants prohibit lights reflection through water which is measured with a nephelometric turbidity meter. Just as smoke in the air causes a hazy appearance, so does turbidity in the water. Hard to see the particles with the naked eye, but a meter will show if they are present. The new requirements suggest we sample at each discharge.  Thus, when a rain event occurs on a construction site  and a discharge occurs, a grab sample must be collected from all the outfalls located on site. The sample will then be tested and the magic number we are all shooting for is 280 NTU or less. However, it will be important to know each state has been given the authority to determine frequency, location and other specifics of sampling.

What else changed in storm water with this ruling?

Non-numeric changes are a big part of the requirements. One example of non-numeric is the protection and/or stabilization of vegetation. Let me clarify, an operator can no longer allow natural vegetation to regrow on the site (example: developing a community and then selling lots to a home builder). The operator must place it in their budget to stabilize the site (lots) with vegetation as soon as construction is completed. The regulations clearly communicate that stabilization must be initiated immediately after 14 days of completion.

There may other non-numeric changes that are listed in the regulations that help control the loss of sediment from a construction site. All of these changes will aid in reducing the amount of sediment entering our waterways. It is also important to note that these non-numeric requirements are effective immediately and are required even if you are not required to conduct sampling from your site.

Is this ruling applicable for all construction sites?

Yes, all sites must at a minimum comply with the non-numeric changes, but only sites that are part of a common plan of development disturbing 20 acres or greater must comply starting August 2011. Sites that are part of a common plan of development disturbing 10 acres are greater must comply in February 2014. NOTE: These rules can and will change once every states general permit expires. The states will have the ability to changes these dates, consrtruction sizes, numeric sampling number, etc.

There is much more to learn, but we ask you contact us for the many more details that are not listed in this blog. Merit is currently scheduling private training for companies across the nation.