Pollution Prevention - Urban Watersheds: Geology, Contamination, and Sustainable Development - page 451

not sufficient to achieve the “fishable and swimmable” goal of the CWA because non-
point sources, especially agricultural and urban runoff, were contributing substantial
amounts of pollution (Humenik et al. 1987). Also in 1987, the USEPA initiated the NPDES
Stormwater program, requiring municipalities with separate storm sewer systems located
in incorporated areas with populations of 100,000 or more to obtain NPDES permits for
stormwater discharges (USEPA 1996). In 1999, Phase II of this program was extended to
smaller municipalities and required permit holders to implement post-construction storm-
water management programs using best management practices (BMPs) in new development
and redevelopment (emphasis by the authors) . Examples of BMPs for stormwater management
include education, road salt management, street cleaning, and erosion control measures,
such as silt fences and covering exposed soil.
Since the overland flow of water in urban areas (stormwater) forms the transport com-
ponent of erosion, stormwater becomes the focal point of pollution prevention methods.
The goal here is not to develop a list of stormwater BMPs; the EPA has a “menu of BMPs”
designed to help communities with their implementation of the Phase II stormwater rules
(USEPA 2010c). Instead, our focus is that given the limitations of the Phase II Stormwater
controls (they only apply to new development or redevelopment), how can we achieve
effective pollution prevention methods for stormwater in older urban areas?
To help answer this question, we now apply the pollution prevention framework used
for point source control to nonpoint sources.
13.4.1 Applying the Source Control Framework to Nonpoint Sources
13.4.1.1 Step 1: Establishing Objectives and Gathering Background Data
Objectives for nonpoint pollution control will vary according to specific watershed condi-
tions and needs. To place this effort on a firm foundation and to obtain the best informa-
tion, the following general objectives are recommended:
• Integrate nonpoint pollution control fully with watershed management/watershed resto-
ration efforts . There is a growing movement to implement nonstructural source
control measures for stormwater (e.g., bioretention, swales, porous pavement) —
collectively referred to as “low-impact development”. Unfortunately, the adoption
of these procedures at larger scales across watersheds is being hampered by (1)
uncertainties in performance and cost, (2) insufficient engineering standards and
guidelines, (3) fragmented responsibilities, (4) lack of institutional capacity, (5) lack
of legislative mandate, (6) lack of funding and effective market incentives, and
(7) resistance to change (Roy et al. 2008). Integration of these efforts with water-
shed-wide initiatives can help overcome some of these obstacles and increase their
extent of implementation.
• Manage the land to achieve better water quality . Most watershed surface areas are
95% land, so proper land management is necessary to improve water quality. For
example, a study of 27 water suppliers conducted by the Trust for Public Land and
the American Water Works Association in 2002 found that the more forest cover in
a watershed, the lower the treatment costs. According to the study, for every 10%
increase in forest cover in the source area, treatment and chemical costs decreased
approximately 20%, up to about 60% forest cover. Approximately 50%-55% of the
variation in treatment costs was explained by the percent of forest cover in the
source area (Ernst et al. 2004).