Supplemental Explanation in Support of BMPs in C&D ELG and NSPS February 15, 2012

1 40 CFR 450.21( d ) Pollution Prevention Measures

. Design, install, implement, and maintain effective pollution prevention measures to minimize the discharge of pollutants. At a minimum, such measures must be designed, installed, implemented and maintained to ( 2 ) 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 stormwat er.

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(1) This B M

P control

s or minimiz

es the discharge of stormwater from the site

.

Materials stored on site, such as building materials, building products, construction wastes, trash, landscape materials, fertilizers, pesticides, herbicides, detergents, sanitary waste and

other materials constitute or can generate pollutants that can be discharged from the site if these materials are exposed to precipitation or to stormwater. For some materials, such as paints, solvents, pesticides/herbicides, etc., it is appropriate to prevent exposure of these materials to precipitation or to stormwater until they are to be used on the site. This can be accomplished by storing these materials in rain

- proof containers, inside vehicles or in other covered areas to prevent their exposure. Trash and other construction debris can be collected and placed in du mpsters or hoppers until these materials can be hauled off

- site for disposal. Tarps or other covers can be placed over materials until they are to be used. The specific controls will depend on the material, its intended use, and the nature of the material. Therefore, EPA believes that permitting authorities should exercise discretion when determining what materials should be prevented from being exposed to precipitation or to stormwater (and should therefore be covered, etc.) and what materials do not need to be prevented from being exposed

to precipitation or stormwater since a material

- by

- material enumeration by EPA is not appropriate.

(2) What EPA do es not mean by this requirement

.

For some materials, such as construction materials, minimizing the exposure to stormwater and precipitation may not be feasible or necessary. For some materials that are designed to be exposed to stormwater after construction, such as pre

- cast concrete bri dge components, steel for transmission towers, power poles, tower components, insulators, conductors, pipes, electrical and other equipment, minimization of exposure to stormwater would be infeasible and/or inappropriate. Also, it would be infeasible to pr event exposure of some materials to precipitation and stormwater. For example, pipe sections for a pipeline construction project are often stored outside in staging areas. Due to the number and size of these materials, covering

these materials would be inf easible and inappropriate. Inert materials, such as stone, bricks, etc., and other materials that are also not expected to contribute pollutants to stormwater, would also likely not be appropriate to mandate no

- exposure to stormwater. Obviously, these mate rials should be stored in areas where they will not be exposed to flowing stormwater, but precipitation falling on these materials and then mixing with stormwater on the site would likely not be of

concern.

( 3 ) In its comments on the proposed C&D ELG/NSPS, NAHB expressed support for non

numeric effluent limitati ons in the form of BMPs like this provision.

In its cover comment letter on the proposed C&D ELG/NSPS, NAHB stated that it “has consistently advocated for an ELG that allows for site

- specif ic selection of BMPs, appropriate sediment basin sizing criteria and the implementation of pollution prevention practices.” NAHB comment cover letter at 2. NAHB stated that EPA’s proposed Option 1, a BMP

- only ELG,Supplemental Explanation in Support of BMPs in C&D ELG and NSPS February 15, 2012

2 “would build upon the significant enviro nmental progress made to date by ensuring that all construction sites meet a minimum standard of excellence by adopting those erosion and sediment controls that have evolved and are now accepted across the country.” Id. NAHB urged EPA to broaden “best ma nagement practices and pollution prevention to ensure these practices can be implemented at every permitted construction site, in all circumstances across the country.” Id. at 3.

In its detailed comments attached to its cover letter, NAHB continued to s upport a BMP

- only ELG to control stormwater discharges from active construction sites. NAHB urged EPA “to remove any requirements to meet numeric effluent limits and proceed with a BMP

- based ELG to control stormwater discharge.” NAHB detailed comments at 38. NAHB claimed that “[i]n the case of EPA's proposed C&D ELGs, the combination of ELG precedent and the fact that EPA is focusing exclusively on stormwater provides irrefutable support for a BMP

- based ELG approach.” Id. at 42. NAHB concluded that “[t ] here is substantial authority for and evidence regarding the success associated with permitting authorities relying on BMP

- based approaches to achieve environmental objectives. EPA also should rely on a BMP

- based approach for the C&D ELG rulemaking.” Id . at 46 (emphasis in original).

In addition, in its redline/strikeout “precisely crafted edits” of EPA’s proposed Option 1, the BMP

only ELG, NAHB suggest ed revision s to proposed 450.21( c )( 6 ) to make that provision read as
follows: “ Minimize the exposure of stormwater to building materials, landscape materials, fertilizers, pesticides, herbicides, detergents, and other liquid or dry products. Implement appropriate chemical spill prevention and response procedures. Permittees should ensure that any significant spills and leaks are addressed appropriately and actions are taken before the next storm event to help prevent the discharge of any related pollutants.” EPA had proposed

“ Implement measures to minimize the exposure of stormwate r to building materials, landscape materials, fertilizers, pesticides, herbicides, detergents, and other liquid or dry products. Implement appropriate chemical spill prevention and response procedures. Any spills and leaks

that do occur shall be immediat ely addressed in a manner that prevents the discharge of any pollutants.” Thus, while NAHB suggested changes to the provision , it did not suggest deleting

the provision , thereby acknowledging, consistent with its overall comments in support of a BMP

only ELG, that taking such measures as detailed, at a minimum, in th is BMP provision as edited by NAHB, is key to controlling and minimizing the discharge of stormwater from active construction sites. See reference to “precisely crafted edits” on page 144 of N AHB’s detailed comments on the proposed ELG/NSPS, as well as the attachment to EPA

- HQ

- OW

- 2008

- 0465

- 1360.

( 4 ) Implementation

The construction stormwater ELG will be implemented in NPDES permits as the applicable technology

- based effluent limitation s in those NPDES permits. The ELG is not directly applicable to any regulated entity . If the permitting authority chooses to copy the ELG verbatim into its draft proposed NPDES permit as the technology

- based effluent limitation, dischargers will have an oppo rtunity to provide comment on the need for more specificity if they are

concerned that the narrative nature of the limit could unfairly subject them to arbitrary
enforcement. Furthermore, in the e vent that the permitting authority does not provide any

add itional specificity, it is t ypical in stormwater permits for active construction for the permitting

authorities to include a requirement to prepare a storm water pollution prevention plan ( SWPPP ) in the permit. While the provisions of the SWPPP are not ef fluent limitations themselves, they indicate how the discharger intends to meet the narrative effluent limitati ons in the permit. AsSupplemental Explanation in Support of BMPs in C&D ELG and NSPS February 15, 2012

3 such

, SWPPPs can be helpful to the regulated entity in demonstrating how they are meeting
their effluent limitations.

In the 2012 CGP

, EPA has implemented this provision by including specific requirements regarding the storage of construction products, wastes, and materials; specific requirements regarding the clean

- up of spills; and specific requirements regarding the disposal of certain

materials.

( 5 ) A ppropriate time for implementation of this BMP in the construction process

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Materials should be prevented from exposure to precipitation and stormwater as they are brought onto the site. If precipitation is forecast, then it may be appropriate to move or provide

cover for materials so as to limit their exposure to precipitation and stormwater. Trash and other debris should be frequently collected and removed so as not to become a source of pollution.