Transcript IECA Sotheast 2009 C&D ELG - Western Slope Safety Council

Effluent Guidelines for Construction
Greg Davis
USEPA
[email protected]
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• EPA promulgated Construction and
Development effluent limitations guidelines
December 1, 2009.
• New rule requires all construction sites
subject to permits to implement erosion and
sediment controls and pollution prevention
measures
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What is an ELG?
 Technology-based standards for control
of wastewater and stormwater discharges
from various categories of industry
 Where ELGs are not sufficient to meet
water quality, water quality based effluent
limitations may apply.
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2-Part ELG for Construction
• Erosion and Sediment Control
Requirements (BMPs) applicable to
all permitted sites
• Numeric limits – 280 NTU limit applicable to
larger projects
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Phased Approach for Numeric Limits
• Numeric effluent limits apply to:
• 20+ acre sites on August 1, 2011
• 10+ acre sites on February 2, 2014
• Requirements must be incorporated into state permits
whenever permits are re-issued
(Colorado’s permit expires in 2012)
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What About Existing Projects?
• For existing projects covered by general
permits, the rule would apply whenever a new
general permit is issued and that project
applies for coverage under the new permit
• For existing project covered by individual
permits, the permitting authority can wait until
a new general permit is issued to issue a new
individual permit
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Erosion and Sediment Control Requirements
•
Control stormwater volume and velocity within the site to
minimize soil erosion;
•
Control stormwater discharges to minimize erosion at outlets
and downstream channel and streambank erosion;
•
Minimize the amount of soil exposed during construction;
•
Minimize the disturbance of steep slopes;
•
Design, install and maintain erosion and sediment controls
considering factors such as precipitation and soil
characteristics;
•
Provide and maintain natural buffers around surface waters,
direct stormwater to vegetated areas to increase sediment
removal and maximize stormwater infiltration, unless infeasible;
and
•
Minimize soil compaction and, unless infeasible, preserve
topsoil.
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Soil Stabilization and Dewatering Requirements
•
Initiate stabilization of disturbed areas immediately
whenever any clearing, grading, excavating or other
earth disturbing activities have permanently ceased,
•
Initiate stabilization immediately when earth
disturbing activities have temporarily ceased and
will not resume for a period exceeding 14 calendar
days.
•
In arid, semiarid, and drought-stricken areas where
vegetative stabilization is infeasible, alternative
stabilization measures must be employed.
•
Discharges from dewatering activities, including
discharges from dewatering of trenches and
excavations are prohibited unless managed by
appropriate controls.
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Pollution Prevention Requirements
• Minimize the discharge of pollutants from equipment and vehicle
washing, wheel wash water, and other wash waters. Wash
waters must be treated in a sediment basin or alternative control
that provides equivalent or better treatment prior to discharge;
• Minimize the exposure of building materials, building products,
construction wastes, trash, landscape materials, fertilizers,
pesticides, herbicides, detergents, sanitary waste and other
materials present on the site to precipitation and to stormwater;
and
• Minimize the discharge of pollutants from spills and leaks and
implement chemical spill and leak prevention and response
procedures.
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Prohibited Discharges
• 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;
• Fuels, oils, or other pollutants used in
vehicle and equipment operation and
maintenance; and
• Soaps or solvents used in vehicle and
equipment washing.
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Surface Outlets
• When discharging
from basins and
impoundments, utilize
outlet structures that
withdraw water from
the surface, unless
infeasible.
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Turbidity Limitation and Monitoring
•
Limit is based on polymer-assisted settling,
but permittees can use any technology
•
Turbidity limitation of 280 NTUs is a Daily
Maximum Value
•
Daily value at each discharge point is
calculated by averaging all samples at that
point
–
•
Individual samples can be above 280
NTU as long as average is below 280
NTU
Permittees can phase land disturbing activities
to stay below the disturbed acreage threshold
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Technologies for Turbidity Control
• Settling (basins or check dams)
• Filtration
– In-ground sand filter
– Geotextile bags
– Practices in channels (fiber check dams,
geotextile products)
• In many cases polymer or flocculant addition
may be necessary
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Turbidity Limitation and Monitoring
• Limitation does not apply to
interstate natural gas pipeline
projects
• Limitation does not apply on days
with precipitation exceeds the
local 2-year, 24-hour storm event
• Sampling required at each
discrete discharge point (basins,
channels, pipes, etc.)
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Sampling Requirements
• Monitoring frequency is up to the permitting
authority, but EPA recommends at least 3 grab
samples per day at each discharge point (during
normal working hours)
• For linear projects, permitting authority can
consider representative sampling instead of
sampling at each discharge point
• Even if permitting authority allows representative
sampling, all discharge points are still subject to
compliance with effluent limitation
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Questions ?
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