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Chapter 7
Construction BMPs
such as sediment control logs/straw wattles, some materials may be biodegradable (straw), but there may
be components of the BMP that biodegrade slowly (stakes) or not at all (plastic netting). Always check
local requirements for guidance on construction BMPs that may remain in place.
Temporary erosion control measures should not be removed until all areas tributary to the temporary
controls have achieved final stabilization. It may be necessary to maintain some of the control measures
for an extended period of time, until the upgradient areas have been fully stabilized, and vegetation has
sufficiently matured to provide adequate cover. Trapped sediment and disturbed soil areas resulting from
the disposal of temporary measures must be returned to final plan grades and permanently stabilized to
prevent further soil erosion.
Whenever post-construction BMPs are used for sediment controls during construction, the plan should
include the steps and actions needed to refurbish these facilities to a fully operational form as postconstruction
BMPs. The final site work will not be accepted by the local jurisdiction until these BMPs
are in final and acceptable form as the original design calls for, which includes lines and grades, volumes,
outlet structures, trash racks, landscaping and other measures specified in the site development plans
prepared by the design engineer.
3.5 2009 Federal Effluent Limitation Guidelines
On December 1, 2009, the EPA published Effluent Limitation Guidelines in the Federal Register
(Volume 74, Number 229, pages 62997-63057) establishing technology-based effluent limitation
guidelines (ELGs) and new source performance standards (NSPS) for the construction and development
industry. This rule requires construction site owners and operators to implement a range of erosion and
sediment control measures and pollution prevention practices to control pollutants in discharges from
construction sites. Additionally, the rule requires monitoring and sampling of stormwater discharges and
compliance with a numeric standard for turbidity in these discharges for larger construction sites (i.e.,
10 acres or more). The rule, including numeric effluent limits, was legally challenged in 2010 and, as of
October 2010, EPA is in the process of reconsidering the numeric effluent limits from the rule. Other
portions of the rule will remain in effect while EPA reevaluates the numeric limits.
In Colorado, unless constructing a federal project or working on an Indian reservation, construction
stormwater discharge permits are issued by CDPHE under the CDPS General Permit for Stormwater
Discharges Associated with Construction Activity (CDPS Permit No. COR-030000). This permit was
first issued in 1997, and is effective through June 30, 2012. It is anticipated that CDPHE will issue a new
general permit in 2012 that will reflect the guidelines, with the possible exception of the numeric limits
which may still be under reevaluation at the time that CDPHE issues the new permit. Existing state
stormwater requirements will remain in effect until a new general permit is issued.
4.0 Overview of Construction BMPs
Construction BMPs include not only erosion and sediment control BMPs, but also material management
and site management BMPs. Related practices include dewatering and construction in waterways, which
are discussed in Sections 6 and 7. The design details and notes for the BMPs identified in this section are
provided in stand-alone Fact Sheets that also include guidance on applicability, design, maintenance, and
final disposition. A key to effective stormwater management at construction sites is to understand how
construction stormwater management requirements change over the course of a construction project, as
summarized in Figure 7-2. Additionally, BMPs vary with regard to the functions they provide.
November 2010 Urban Drainage and Flood Control District 7-11
Urban Storm Drainage Criteria Manual Volume 3