On Feb. 1, the Environmental Protection Agency
(EPA) began enforcing new standards for effluent from construction sites of 1 acre or more. Technology-based Effluent Limitations Guidelines
and New Source Performance Standards now ensure that precipitation does not cause the erosion of sediments or wash construction materials, chemicals and solvents from construction sites.
This action represents the first stage of a phased implementation of increasingly stringent standards. Beginning in August 2011, the EPA will require construction sites to sample stormwater discharges. Pending the outcome of ongoing litigation, construction sites may have to meet numeric limits for turbidity as well.
The EPA has long recognized the adverse impacts construction activities can have on water quality. As surface water drains from construction sites, it can pick up hazardous chemicals, debris and sediment that are then carried to water bodies—ultimately impacting aquatic habitats and impeding waterways.
Prior to Feb. 1, certain firms engaged in construction activity were required to obtain National Pollutant Discharge Elimination System
(NPDES) permits and to implement control measures to manage discharges from sites if the construction:
- resulted in the disturbance of 5 acres or more; or
- resulted in the disturbance of less than 5 acres of total land area that is part of a common plan for development or sale that disturbs 5 acres or more.
The EPA’s new regulations target small construction activities that disturb 1 or more acres and less than 5 acres of land, or are part of a larger plan or development that disturbs 1 or more and less than 5 acres of land.
Under the NPDES program, construction dischargers obtain coverage either through general permits or individual permits. General permits apply to classes of dischargers (e.g., construction dischargers). Any discharger that wants to use a permit must file a notice of intent. Each state and tribe sets its own general permit requirements, but the EPA requires all permits to include technology-based effluent limitations.
If such limitations are not sufficient to meet applicable water quality standards, the permit must contain an added layer of water quality-based effluent limitations. Individual permits may be required or requested by any permitting authority or discharger. Minimum Performance Standards
The EPA’s new rule, for the first time, imposes minimum national performance standards and monitoring requirements through NPDES permits. The national program does not prevent a state or locality from imposing stricter requirements.
Beginning Aug. 1, 2011, construction sites that disturb 20 or more acres will be required to meet a series of non-numeric effluent limitations applicable to stormwater discharges and dewatering activities. The goal of the limitations is to reduce the amount of sediment, turbidity, total suspended solids and other pollutants released into the nation’s waterways.
More specifically, these non-numeric controls require:
Numeric Limitations Under Review
- Erosion and sediment controls. Permittees are required to install erosion and sediment controls sufficient to minimize the discharge of pollutants. The controls must minimize stormwater volume and velocity within the site; control stormwater discharges to minimize erosion outlets and downstream bank erosion; minimize the amount of soil exposed during construction; minimize disturbance of steep slopes; minimize sediment discharges from the site; provide natural buffers (e.g., direct stormwater to vegetated areas); and minimize soil compaction.
- Soil stabilization. Permittees are required to initiate soil stabilization measures whenever any clearing, grading, excavating or other earth-disturbing activities have permanently ceased or temporarily ceased for a period of 14 or more days.
- Dewatering. Permittees are required to minimize the discharge of pollutants from dewatering trenches and excavations.
- Pollution prevention. Permittees are required to implement measures to minimize the discharge of pollutants from vehicle washing and other wash waters; building/landscape materials, products, waste, fertilizers, pesticides, herbicides, detergents and sanitary waste; and spills and leaks. Additionally, the rule prohibits the discharge of wastewater from washout of concrete (unless managed by an appropriate control); wastewater from washout and cleanout of stucco, paint, form release oils, curing compounds and other construction materials; and fuels, oils or other pollutants used in vehicle and equipment operation and maintenance.
The EPA originally required construction sites that disturb 10 or more acres of land to monitor discharges from the site and comply with the numeric effluent limitation of 280 nephelometric turbidity units (NTU), expressed as a maximum daily discharge limitation. This numeric limitation was successfully challenged in litigation and has been remanded by the EPA pending further review and analysis.
It is likely the 280 NTU limit will be increased in a subsequent rulemaking. In such case, permittees for sites disturbing 10 acres or more likely would be required to sample stormwater discharges and report the levels of turbidity present to their permitting authority. Permitting authorities would be required to incorporate this turbidity limitation into their permits, and permitees would be required to implement control measures.
The EPA will not dictate specific technologies to meet the numeric limit; permittees will retain the flexibility to select their own management practices or technologies.
Contractors should be aware of the non-numeric controls currently required and prepare for the new monitoring and effluent limitations that likely will take effect following the EPA’s re-analysis. Contractors should account for these factors when submitting proposals and bidding on contracts, as they have the potential to increase the compliance costs associated with a construction project.