Stormwater Management: EPA Pilot Project to Increase Use of Green Infrastructure Could Benefit from Documenting Collaborative Agreements
Published: 2017-09-28T00:00:00

Fast Facts:
Stormwater from streets and sewers can flow into rivers and be a major source of pollution. EPA requires cities and utilities to reduce this type of pollution. Traditional remedies can be expensive for local communities but green infrastructure can be a less expensive option.
Green infrastructure uses natural processes and materials (like green roofs) to slow stormwater so it is absorbed and filtered by the soil. In 2016, EPA launched a pilot project to help communities develop long-term green infrastructure plans.
We recommend that EPA document agreements with community stakeholders on how they will collaborate in developing these plans.

Highlights:
section_title: Why GAO Did This Study
paragraphs: Urban stormwater runoff is a major contributor to pollution in U.S. waters. Municipalities historically managed stormwater with gray infrastructure. In 2007, EPA began encouraging the use of green infrastructure to manage stormwater and reduce the need for gray infrastructure.
GAO was asked to examine the use of green infrastructure by municipalities to meet EPA's stormwater requirements. This report (1) describes the extent to which selected municipalities are incorporating, and funding, green infrastructure in stormwater management efforts; (2) describes what challenges, if any, municipalities reported facing in incorporating green infrastructure into stormwater management efforts; and (3) examines efforts EPA is taking to help municipalities use green infrastructure.
GAO surveyed two nongeneralizable samples totaling 31 municipalities with stormwater permits or consent decrees for CSOs and interviewed EPA officials to examine EPA efforts to help municipalities use green infrastructure. The municipalities were randomly selected from lists of municipalities that are required to have permits and have consent decrees.
section_title: What GAO Found
paragraphs: Almost all 31 municipalities GAO surveyed reported using green infrastructure to comply with their Clean Water Act permits or combined sewer overflow (CSO) consent decrees. The Environmental Protection Agency (EPA) regulates stormwater pollution under the Clean Water Act, which requires municipalities to obtain permits to discharge stormwater into waterbodies. EPA has also entered into consent decrees with municipalities that have CSOs—events where raw sewage is discharged into waterbodies. Green infrastructure uses natural processes to manage stormwater, such as capturing stormwater so it can seep into soil (see figure). However, of 27 municipalities responding, 15 reported that less than 5 percent of the area subject to their permit or consent decree drained into green infrastructure, with the remaining area draining into gray infrastructure, such as concrete sewers, or directly to waterbodies. Most of the municipalities reported funding green infrastructure with fees and general revenues.
Of the 31 municipalities GAO surveyed, 26 reported that green infrastructure was more challenging than gray infrastructure in aspects of infrastructure development, such as developing project operation and maintenance cost estimates. Nevertheless, 25 of these municipalities reported instances where they used green infrastructure even though it was more challenging. Some municipalities reported that they were less familiar with green infrastructure but used it anyway because it performed better or it provided additional benefits, the community wanted to use it, and the municipality saw an opportunity to learn about green infrastructure.
EPA provides multiple resources to educate and assist municipalities on the use of green infrastructure. In 2016, the agency launched a pilot project with five municipalities to encourage states, communities, and municipalities to develop long-term stormwater plans to increase their use of green infrastructure. Key to the success of the pilot project is collaboration among many stakeholders from across each community, such as members of the local utility, transportation, and recreation departments, as well as local organizations. GAO has previously identified key considerations, such as documenting agreements on how to collaborate that can benefit collaborative efforts. However, EPA has not yet documented collaborative agreements with pilot stakeholders. EPA could better assure that the stakeholders will successfully develop long-term stormwater plans if it documents how the stakeholders will collaborate.
section_title: What GAO Recommends
paragraphs: GAO recommends that EPA document agreements, when working with municipalities and other stakeholders, on how they will collaborate when developing long-term stormwater plans. EPA generally agreed with GAO's recommendation and plans to implement it over the next 12 to 18 months.

section_title: Letter
paragraphs: Stormwater from urban areas is a major contributor to pollution in the  nation’s waterbodies and can contribute to disease outbreaks and beach  and shellfish bed closings, as well as flooding. Stormwater—rain or snow  that runs off paved surfaces or other impervious areas into water  bodies—may contain pollutants such as bacteria, chemicals, and debris  picked up as water runs over such surfaces. The Environmental  Protection Agency (EPA) regulates stormwater pollution through the  Clean Water Act’s National Pollutant Discharge Elimination System  (NPDES) program, under which some municipalities and others that  operate sewer systems must obtain NPDES permits to discharge  stormwater into nearby water bodies, such as creeks, lakes, and rivers.
In 1987, Congress amended the Clean Water Act directing EPA to  establish a program to regulate stormwater pollution. In 1990 and 1999,  EPA issued regulations under the NPDES program requiring certain  municipalities to have permits, depending on the size of the population  served by the sewer system. The permits prohibit non-stormwater  discharges into storm sewers and require controls, including best  management practices, to reduce pollutant discharges to the maximum  extent practicable.
Municipalities have historically addressed stormwater using gray  infrastructure, such as sewers consisting of concrete pipes and channels,  designed to move stormwater quickly away from urban areas into nearby  water bodies. In 2007, EPA began to promote the benefits of using green  infrastructure to reduce stormwater pollution. Green infrastructure is  designed to use natural processes to slow and capture stormwater and  filter out pollutants, which can reduce the need for additional gray infrastructure to manage stormwater. Green infrastructure includes  practices such as disconnecting downspouts from sewers, which allows  stormwater to flow over land or other permeable areas and seep into the  soil, and physical structures such as bioswales, which drain runoff into  vegetated areas that slow and filter stormwater, allowing it to seep into  the soil.
A sewer system that collects stormwater can be separate from, or  combined with, a sewer system that carries wastewater, such as raw  sewage, from households, businesses, industrial plants, or other  developments. Systems that move stormwater from yards, parking lots,  streets, and other open areas and drain it directly into a water body are  called municipal separate storm sewer systems. Other systems, called  combined sewer systems, carry both stormwater and wastewater in the  same pipes to a wastewater treatment plant. During storm events,  combined sewer systems can overflow and release untreated wastewater  into nearby water bodies. These types of releases are called combined  sewer overflows (CSO). EPA has identified more than 850 municipalities  with combined sewer systems, primarily in the Northeast and Midwest  regions of the United States. EPA has taken enforcement actions against  municipalities with CSO events and has negotiated more than 50 consent  decrees with municipalities, requiring them to take corrective actions to  reduce the amount of untreated wastewater flowing into water bodies.  Nationally, drinking water and wastewater utilities face an estimated $655  billion in costs to rebuild and replace their infrastructure, including $48  billion for corrective actions to treat CSOs. In some cases, according to  EPA and interest groups, using green infrastructure may cost less than  using gray infrastructure to help meet permit requirements and provisions  specified in consent decrees.
You asked us to examine the use of green infrastructure by municipalities  to meet EPA’s stormwater requirements. This report (1) describes to  what extent selected municipalities are incorporating green infrastructure  into their efforts to comply with NPDES permits and consent decrees that  address CSOs, and what is known about funding for such efforts; (2)  describes what challenges, if any, these municipalities report facing to  incorporate green infrastructure into their efforts to comply with those  permits and consent decrees; and (3) examines efforts EPA is taking to  help municipalities use green infrastructure.
To address all three objectives, we conducted a survey of representatives  of 31 municipalities, including representatives of 20 municipalities with  NPDES permits and representatives of 11 municipalities that have  entered into consent decrees with EPA to address CSOs. Our sample of  31 municipalities cannot be generalized to all municipalities in the United  States; however, we selected these municipalities at random from a  range of geographic locations and a range of sizes. We randomly  selected the 20 municipalities with permits from a list of more than 5,000  municipalities that EPA identified in its 1999 rule on the NPDES  stormwater program. We restricted our selection of municipalities to those  in the 50 states and Washington, D.C. We stratified our sample of  municipalities with permits by size and location. We randomly selected  the 11 municipalities that have entered into consent decrees with EPA  from a list of 36 municipalities with consent decrees that EPA provided to  us. These were consent decrees that EPA entered into with municipalities  in the 50 states or Washington, D.C., after August 2007 when EPA began  encouraging the use of green infrastructure to address the requirements  of permits and enforcement activities, such as consent decrees. An  analysis of these 36 consent decrees showed that about half included  some reference to green infrastructure and about half involved  municipalities in the Midwest. We stratified our sample of 11  municipalities with consent decrees to represent these two  characteristics. Figure 1 shows the location of the municipalities with  permits and consent decrees included in our survey.
The questions we asked municipalities in our survey focused on (1) the  extent to which the municipalities were using green infrastructure to  comply, at least in part, with requirements of their permits or consent  decrees; (2) the amount and source of capital expenditures for green  infrastructure to comply, at least in part, with requirements of their permits  or consent decrees; and (3) the challenges the municipalities may have  experienced in using or considering green infrastructure to comply, at  least in part, with requirements of their permits or consent decrees.
The time frames for which we asked for information from the survey  respondents varied by the questions we asked and whether a municipality  was included in our survey because it has an NPDES permit or a consent  decree to address CSOs. For questions to municipalities with permits  about the extent to which the municipalities were using green  infrastructure and questions about the challenges the municipalities may  have experienced in using or considering green infrastructure, we asked  for information for the approximately 5-year period prior to our survey. For  questions to municipalities with consent decrees, we did not specify a  time frame for these questions. For information on the amount and source  of capital expenditure for municipalities with permits and municipalities  with consent decrees, we asked survey respondents for the information  from the respondents’ last 3 completed fiscal years. We limited these  questions to 3 fiscal years to reduce the work burden on the respondents.
For the purposes of our survey, we define gray infrastructure as all  stormwater infrastructure that is not considered green infrastructure. We  conducted our survey over the phone from November 2016 through April  2017. To examine efforts EPA is taking to help municipalities use green  infrastructure to manage stormwater, we interviewed EPA officials in the  Office of Wastewater Management and examined documents and other  resources available on EPA’s website regarding green infrastructure.
For all three objectives, we reviewed pertinent documents and studies  about green infrastructure and stormwater management from EPA, other  federal agencies, public interest groups, and others. We also interviewed  EPA officials in the agency’s Office of Wastewater Management and  Office of Enforcement and Compliance Assurance, as well as  representatives from several public interest groups, about municipalities’  use of green infrastructure. Further information about the scope and  methodology of our review is presented in appendix I, and the  questionnaires administered to the municipalities with NPDES permits  and the municipalities with CSO consent decrees are presented in  appendix II.
We conducted this performance audit from February 2016 to September  2017 in accordance with generally accepted government auditing  standards. Those standards require that we plan and perform the audit to  obtain sufficient, appropriate evidence to provide a reasonable basis for  our findings and conclusions based on our audit objectives. We believe  that the evidence obtained provides a reasonable basis for our findings  and conclusions based on our audit objectives.
subsections: section_title: Background
paragraphs: This section provides information on the Clean Water Act and stormwater  management including green infrastructure.
subsections: section_title: Clean Water Act and Stormwater Management
paragraphs: The objective of the Clean Water Act is to “restore and maintain the  chemical, physical, and biological integrity of the nation’s waters.” The  act generally prohibits the discharge of pollutants from “point sources”— such as discharge pipes from industrial facilities and wastewater  treatment plants––without an NPDES permit. The act specifies that  NPDES permits may not be issued for a term longer than 5 years.
In 1987, Congress amended the Clean Water Act to require that EPA  implement a comprehensive national program for addressing stormwater  discharges; EPA implemented the program in two phases. In the first  phase, EPA regulated stormwater discharges from large and medium  municipal separate storm sewer system. In the second phase, EPA  extended these requirements to smaller systems. Municipalities include  cities, towns, villages, or other public entities that provide residents with  services, such as drinking water and sewage treatment. Municipalities  can have one or both types of stormwater systems, a municipal separate  storm sewer system or a combined sewer system. Figure 2 illustrates the  components of the two types of systems and how a CSO occurs.
In 1990, EPA issued a regulation implementing the first phase of the  stormwater program, requiring municipalities serving populations of  100,000 or more to obtain permits for stormwater discharges. In 1999,  EPA implemented the second phase by expanding NPDES permit  requirements to smaller municipalities. Generally, permits effectively  prohibit non-stormwater discharges into storm sewers, and require  controls to reduce pollutant discharges to the maximum extent  practicable, including the use of best management practices. These  practices generally include identifying and eliminating illicit discharges;  preventing construction site runoff and post-construction site runoff; and  preventing pollution from certain commercial, industrial, and residential  areas. Such practices could also include distributing materials with utility  bills to help educate the public on activities like cleaning up pet waste and  household chemicals, implementing street sweeping to eliminate trash  and debris, and training and certifying construction contractors.
To manage CSO pollution, in 1994, EPA issued its Combined Sewer  Overflow Control Policy, which provides guidance on how to meet the  Clean Water Act’s pollution control goals through NPDES permits issued  to municipalities with combined sewer systems. Specifically, the policy  provides guidance on coordinating the planning, selection, and  implementation of CSO controls that meet the requirements of the Clean  Water Act. In 2000, Congress amended the Clean Water Act to require  that NPDES permits for discharges from combined sewer systems  comply with EPA’s Combined Sewer Overflow Control Policy. Actions  that can be taken to reduce the number and volume of discharges from a  combined sewer system can include separating storm sewer and sanitary  sewer systems and building larger tunnels to hold stormwater runoff until  it can be treated and discharged by a wastewater treatment plant.
When Clean Water Act requirements are violated—for example, when a  municipality has an unauthorized CSO event—EPA and states may,  among other things, bring suit in court. These suits can result in consent  decrees under which a municipality agrees, for example, to take  corrective actions to reduce the number and volume of CSO events. In  1998, EPA’s Office of Enforcement and Compliance Assurance began a  National Enforcement Initiative to focus enforcement action on keeping  raw sewage and contaminated stormwater out of the nation’s waters.  According to an EPA official, the agency has addressed noncompliance  with stormwater and wastewater requirements of the Clean Water Act by  entering into consent decrees with over 50 municipalities from 1998  through 2016.
section_title: Green Infrastructure
paragraphs: Municipalities use green and gray infrastructure to manage stormwater  and meet the requirements of permits and consent decrees. Gray  infrastructure refers to sewer structures that are typically made of  materials, such as concrete or metal, designed to collect and channel  stormwater runoff from impervious surfaces, such as city streets and  parking lots, to a wastewater treatment plant or nearby creeks, lakes, and  rivers. Green infrastructure includes practices and structures to manage  stormwater that use or mimic natural processes to slow stormwater  runoff, filter pollutants from the runoff, and facilitate stormwater storage  for future use or replenishing groundwater and aquifers. Figure 3  illustrates how green infrastructure allows stormwater to penetrate (seep  into) the soil and replenish groundwater and aquifers.
Municipalities can meet permit and CSO consent decree requirements  using either green or gray infrastructure, or a combination of both. For  example, both types of infrastructure can limit the amount of pollutants  that stormwater washes into nearby water bodies. Green infrastructure  can filter out the pollutants, and gray infrastructure can convey the  combined stormwater and wastewater to a wastewater treatment plant.  Similarly, both types of infrastructure can prevent CSO events. Green  infrastructure can reduce the volume of stormwater entering a combined  sewer, and if gray infrastructure has sufficient capacity, the combined  sewer will not be overwhelmed during storm events.
Since 2007, EPA has encouraged municipalities to use green  infrastructure to help meet the requirements of permits and CSO consent  decrees. In April 2007, the EPA Administrator entered into an agreement  with state, environmental, and wastewater utility groups to promote the  use of green infrastructure in reducing stormwater pollution and mitigating  CSOs. In August 2007, EPA issued a memorandum stating that EPA  regional offices and states may encourage the use of green infrastructure,  where appropriate, in meeting permit requirements and CSO consent  decrees. According to EPA officials we interviewed, the agency worked  with a number of partners, including other federal agencies and nonprofit  groups involved in water management, conservation, and housing and  development, to promote the use of green infrastructure. EPA developed  a strategic plan to help communities use green infrastructure in 2008 and  updated it in 2011 and again in 2013. EPA’s latest plan, the 2013 Green  Infrastructure Strategic Agenda, includes five goals:
Green infrastructure practices are embedded in federal agency  programs.
Green infrastructure language in permitting and enforcement actions  is common practice.
Data on the design, performance, costs, and benefits of green  infrastructure is known and readily available.
Decrease the financial burden to communities of installing and  maintaining green infrastructure.
Communities across the country are networking and exchanging  information on the best green infrastructure approaches.
EPA’s website illustrates different types of green infrastructure, with 11  examples. Figure 4 shows the 11 examples of green infrastructure listed  on EPA’s website.
section_title: Surveyed Municipalities Use of Green Infrastructure to Manage Stormwater Is Limited and Funded through General Revenues and Fees Charged to Utility Customers
paragraphs: Most of the 31 municipalities we surveyed use green infrastructure to  comply with NPDES permits or CSO consent decrees, but almost half  said that less than 5 percent of the area covered by their permits or  consent decrees drains into green infrastructure. About three-quarters of  the municipalities said that they fund green infrastructure through general  revenues and stormwater fees charged to utility customers or residents of  the municipality.
subsections: section_title: Most Surveyed Municipalities Are Using Green Infrastructure in Their Efforts to Comply with Permits and CSO Consent Decrees, but About Half Reported Using It to a Limited Extent
paragraphs: Of the 31 municipalities we surveyed, 30 reported using at least 1 of the  11 examples of green infrastructure presented on EPA’s website to help  meet the provisions of their permits since 2012 or the provisions of their  CSO consent decrees. For each of the 11 green infrastructure types,  municipalities reported whether to comply, at least in part, with their  permit or consent decrees they (1) used or installed the type of green  infrastructure themselves or (2) encouraged or required property owners  to use or install the type of green infrastructure. Twenty-eight  municipalities reported that they used or installed a type of green  infrastructure and encouraged or required property owners to use or  install a type of green infrastructure. Two municipalities reported that they  had not used or installed any green infrastructure themselves but had  encouraged or required property owners to use or install a type of green  infrastructure. Of the 11 types, the 3 most used or installed by  municipalities—or that municipalities encouraged or required their  customers to use—were downspout disconnection, rain gardens (also  known as bioretention), and permeable pavement. Figure 5 illustrates  how many of the 30 municipalities reported using or installing 1 or more of  the 11 types of green infrastructure themselves and how many  municipalities reported that they encouraged or required private property  owners to use or install a type of green infrastructure.
In addition to the green infrastructure types identified in figure 5, the  municipalities we surveyed also identified other green infrastructure that  they used to help meet permit or consent decree requirements. For  example, one municipality said that it used habitat restoration and similar  efforts to address stormwater runoff. Another municipality reported using  an infrastructure system that collected water underneath a parking lot  where it could penetrate the soil below the paved surface.
The one municipality that reported not using green infrastructure to help  comply with the provisions of its consent decree said that there was  insufficient public land on which to install green infrastructure and that the  type of soil in the area subject to the decree, blue marine clay, is not  permeable enough to allow green infrastructure to filter water through the  soil. However, the same municipality said that the community that it  served was generally receptive to using green infrastructure to manage  stormwater and that it uses green infrastructure in other areas of the  community not included in the terms of the consent decree.
Of the 30 municipalities that reported using green infrastructure to help  meet the provisions of their permits or CSO consent decrees, many of  them also reported on the percentages of the areas subject to permits or  consent decrees that drain into green infrastructure, with the remaining  areas draining into gray infrastructure or directly into creeks, lakes, or  rivers. Twenty-seven municipalities provided us with information about  how much of the areas subject to permits or consent decrees drains into  green infrastructure and how much drains into gray infrastructure or  elsewhere. Of these 27 municipalities, 15 reported that less than 5  percent of the relevant areas drained into green infrastructure, while 6  municipalities reported that more than 20 percent of the area subject to  permits or consent decrees drained into green infrastructure. The  remaining 6 municipalities reported that from 5 percent to 20 percent of  the relevant areas drains into green infrastructure. Figure 6 provides  additional information on the percentages of areas subject to  municipalities’ permits or consent decrees that drain into green  infrastructure.
section_title: Most Surveyed Municipalities Are Funding Green Infrastructure through General Revenues or Stormwater Fees Charged to Utility Customers
paragraphs: Of the 30 municipalities that reported using green infrastructure to help  comply with the provisions of their permits or CSO consent decrees, 24  municipalities reported using general revenues or specific fees for  stormwater management levied on utility customers or municipal  residents to fund capital expenditures for green infrastructure over their  last 3 fiscal years. Of the remaining 6 municipalities, 2 reported using  sales tax revenues or federal grant funding as the sole source of funding,  2 said that they had no capital expenditures for green infrastructure in the  last 3 fiscal years, and 2 did not respond to the question.
Of the 24 municipalities that reported using general revenues or  stormwater fees to fund capital expenditures for green infrastructure to  help comply with the provisions of permits or CSO consent decrees, 14  reported that they also used funding from one or more additional sources.  Six reported that they also used federal grant funding to help pay for  capital expenditures on green infrastructure, 5 said that they also used  funding from their state’s Clean Water State Revolving Fund, and 5 said  that other nonfederal grants were a source of funding for their green  infrastructure. Some municipalities also identified additional sources of  revenue to fund capital expenditures for green infrastructure, including  fees on new development.
Of the 30 municipalities that reported using green infrastructure to meet  the provisions of their permits or CSO consent decrees, 17 provided  information comparing their capital expenditures for green infrastructure  to capital expenditures for gray infrastructure. The remaining  municipalities either did not have information that distinguished between  capital expenditures on green infrastructure and gray infrastructure or  they did not provide us with that information. The amount that the 17  municipalities reported spending on capital expenditure for green  infrastructure varied from a 3-year average of about $5,000 to about $5.9  million. The amount that the municipalities reported spending on capital  expenditure for gray infrastructure varied from a 3-year average of about  $18,000 to about $208.2 million. Of the 17 municipalities that provided  data comparing their capital expenditures for green infrastructure to  capital expenditures for gray infrastructure, 11 (65 percent) reported  spending approximately 20 percent or less of capital expenditures on  green infrastructure, including 7 municipalities that reported spending less  than approximately 5 percent on green infrastructure. Conversely, 6 of the  17 municipalities reported spending more than approximately 20 percent  of capital expenditures on green infrastructure, including 3 municipalities  that reported spending more than 60 percent on green infrastructure.  Overall, the 17 municipalities reported spending an average of about 24  percent of their capital expenditures for meeting the provisions of their  permits or CSO consent decrees on green infrastructure, with the  remaining amount spent on gray infrastructure.
section_title: Surveyed Municipalities Reported That Using Green Infrastructure Was More Challenging Than Using Gray Infrastructure but Also Reported Continuing to Use It
paragraphs: Most of the 31 municipalities (26) we surveyed reported that one or more  aspects of infrastructure development involved with projects to help meet  the provisions of their NPDES permits or CSO consent decrees were  usually more challenging when using green infrastructure than when  using gray infrastructure. However, the municipalities also reported  continuing to use green infrastructure.
In our survey, we asked the 30 municipalities that reported using green  infrastructure to help meet the provisions of their permits or CSO consent  decrees about eight aspects of infrastructure development that may have  challenged municipalities when using green infrastructure. For each  aspect, we asked municipalities if the aspect was usually more  challenging for green infrastructure, usually less challenging, or about the  same when compared to gray infrastructure.  1.  obtaining land to install green infrastructure,  2.  developing capital expenditure estimates for green infrastructure,  3.  developing operation and maintenance estimates for green  4.  designing and engineering green infrastructure,  5.  installing green infrastructure,  6.  overall cost of using green infrastructure,  7.  confidence in the effectiveness of green infrastructure, and  8.  political and public opinions regarding green infrastructure.
As shown in figure 7, 15 of 30 municipalities reported that four or more of  the eight aspects were usually more challenging for green infrastructure  than for gray infrastructure. One municipality said that all eight of the  aspects were usually more challenging for green infrastructure than for  gray infrastructure. Two municipalities reported that no aspects were  usually more challenging for green infrastructure than for gray  infrastructure.
Municipalities most often cited the following aspects of infrastructure  development as being more challenging for green infrastructure than for  gray infrastructure: developing a capital expenditure estimate, developing  an operation and maintenance cost estimate, and designing and  engineering a project. Of the 30 municipalities that reported using green  infrastructure, 22 reported that developing an operation and maintenance  cost estimate was usually more challenging than doing so for gray  infrastructure, while none said that it was usually less challenging.
Similarly, 16 municipalities reported that developing a capital expenditure  estimate for green infrastructure was usually more challenging than doing  so for gray infrastructure, while none said that it was less challenging.  Finally, 16 municipalities reported that designing and engineering a  project was usually more challenging for green infrastructure than for gray  infrastructure, while 3 said that it was usually less challenging. Figure 8  shows the number of municipalities that reported for each of the eight  aspects whether they were usually more challenging, usually about the  same, or usually less challenging when using green infrastructure  compared to using gray infrastructure. Figure 8 also shows that political  and public opinion regarding green infrastructure was the one aspect that  municipalities cited as usually less challenging for green infrastructure  than for gray infrastructure.
In explaining why these aspects of infrastructure were more challenging  for green infrastructure, municipalities most commonly reported that they  were not familiar with green infrastructure. For example, when describing  their unfamiliarity with green infrastructure, representatives of one  municipality said that with gray infrastructure, the maintenance activities  and costs associated with traditional sewers are known from experience.  For green infrastructure, however, they said that they needed to increase  cost estimates for maintenance activities to account for unforeseen  events. Representatives of another municipality, referring to gray  infrastructure, said they know what it costs to put a pipe in the ground but  do not have the skill set or experience to estimate the capital costs of  green infrastructure. Discussing the costs associated with maintaining  green infrastructure, representatives of another municipality said they  hired staff with horticultural expertise to maintain rain gardens because  they were unsure about the requirements necessary to maintain them.  Another municipality said that it had difficulties finding qualified personnel  to assist its engineers with green infrastructure.
Of the 26 municipalities that reported that green infrastructure was usually  more challenging than gray infrastructure for at least one aspect, 25  reported that there were instances where they used green infrastructure  anyway. In describing instances where they used green infrastructure  even though it was more challenging, some municipalities reported that  they continued to use green infrastructure to help comply with their  permits or CSO consent decrees for three primary reasons: they saw  using green infrastructure as a learning opportunity, they believed that  green infrastructure would perform better or provide additional benefits  compared to gray infrastructure, or the community wanted to use green  infrastructure. Municipalities expressed a desire to learn from their  experiences with green infrastructure. For example, a municipality said  that it had to rebuild some green infrastructure—add new soil and replant  vegetation—because it let maintenance slide because of budget issues.  Representatives of this municipality said that understanding how to plan  appropriately for operation and maintenance is part of the learning  process associated with using green infrastructure. Another municipality  was more specific, with representatives saying that the city had installed  permeable pavement on a section of street as an opportunity to learn  about permeable materials, especially the maintenance needed to ensure  that permeable pavement continues to function properly.
Some municipalities reported that using green infrastructure was a better  option than using gray infrastructure to address their stormwater  management needs. For example, representatives of one municipality  said that although they had less experience with green infrastructure, they  used it anyway because it was a better option than using pipes and  concrete to reduce the flow of stormwater and the amount of  contaminants in stormwater. Representatives of another municipality said  that they used green infrastructure because it met other project  objectives: it was more aesthetically pleasing, it “fit” into the neighborhood  better, and it replenished groundwater. These municipality  representatives noted that most of the town’s water comes from  groundwater wells.
Some municipalities also reported that they were committed to using  green infrastructure even though it was more challenging than using gray  infrastructure on one or more aspects. For example, representatives of  one municipality said that their city made a pledge to use green  infrastructure. They said the city made the investment and set goals for  green infrastructure, and although it is more difficult to generate cost  estimates, the municipality continues to pursue green infrastructure.  Another municipality said that there was not much data on the long-term  costs of caring for the plants used in bioswales under the drought  conditions that the municipality was currently experiencing. Nevertheless,  the officials said the municipality installed the bioswales because doing so  was supported by the public and an environmentally conscious city  council interested in aesthetics and habitat restoration.
Conversely, of the 26 municipalities that reported that at least one aspect  was usually more challenging when using green infrastructure than when  using gray infrastructure, 19 reported instances where they were  discouraged from using green infrastructure because it was more  challenging than using gray infrastructure. We asked municipalities to  describe these instances.
Some municipalities reported that they were discouraged from using  green infrastructure because they were not familiar with it, because  conditions specific to the area under consideration were not conducive to  using green infrastructure, and because green infrastructure was more  expensive than gray infrastructure. For example, describing their  unfamiliarity with green infrastructure, representatives of one municipality  said that because they were trying to meet the provisions of their consent  decree, they needed an option that they had high confidence would meet  the provisions. They believed that green infrastructure was not a proven  technology. Representatives from another municipality said that while  there had been a high turnover in city engineers and that the newer staff  was amenable to using green infrastructure, the longer tenured engineers  who were reluctant to use green infrastructure had an outsized influence  on whether the engineering department would do so.
Several of the municipalities reported that they were discouraged from  choosing green infrastructure because conditions in the area under  consideration were not conducive to using green infrastructure, including  that there was not enough land in the right place to use green  infrastructure or that the area was too arid. For example, representatives  from one municipality said that they were considering bioretention  measures to reduce CSOs, but there was not enough available land to  make this option viable. They said that because of the topography of the  town, any bioretention measures would need to be placed near the center  of town, but because it was the center of town, there was no room for  bioretention measures. Representatives from another municipality said  that widening a road to meet fire protection requirements consumed the  green space available for green infrastructure and that buying a right of  way was cost prohibitive. Representatives from a third municipality said  that installing green infrastructure in a city’s historic district would change  the character of the area and could consume limited parking spaces— thus engendering negative public opinion. Municipalities also said that  arid conditions discouraged them from installing green infrastructure in  some instances. For example, representatives from one municipality said  that because their municipality is in a semiarid climate that makes it  difficult to establish grasses, they try to predict whether the upcoming  season will be wet or dry and install green infrastructure accordingly.  They said that if they do not predict correctly, the plants will die and the  funds spent on green infrastructure will have been wasted.
Several municipalities also reported that they were discouraged from  using green infrastructure because it was more expensive than using gray  infrastructure. For example, representatives from one municipality said  that green infrastructure was more costly than gray infrastructure because  of the cost of the land that would need to be purchased to install it.  Representatives from another municipality said that green infrastructure  would need to be installed in a flat area near the river and that in some  instances the city did not own the surface area necessary to install green  infrastructure but did own an easement to install gray infrastructure  underground. The representatives said that the city was unable or  unwilling to purchase such surface rights. Representatives from a third  municipality said they did not have the in-house expertise to design green  infrastructure and were discouraged from using green infrastructure  because of the cost to hire outside consultants with that expertise.
section_title: EPA Helped to Facilitate Municipalities’ Use of Green Infrastructure, but in Launching a New Pilot Project Has Not Yet Developed Collaboration Agreements with Municipalities
paragraphs: Over the last 10 years since EPA began encouraging the use of green  infrastructure to manage stormwater, the agency’s efforts have provided  information, technical assistance, and funding to help municipalities use  green infrastructure. In addition, in 2016, EPA began a pilot project to  assist five municipalities in developing long-term stormwater plans that  would allow more time to incorporate green infrastructure practices but  has not yet developed written agreements documenting how they will  work together to collaborate.
subsections: section_title: EPA Has Provided Information, Technical Assistance, and Funding and Launched a Pilot Project to Assist Municipalities in Developing Stormwater Plans That Include Green Infrastructure
paragraphs: Since 2007, when EPA began encouraging the use of green infrastructure  to manage stormwater, EPA has provided information, technical  assistance, and funding for green infrastructure to help municipalities  incorporate green infrastructure into their stormwater systems. The goals  of the green infrastructure program, as described in EPA’s 2013 Green  Infrastructure Strategic Agenda, are (1) embedding green infrastructure in  federal agencies; (2) making green infrastructure language in permitting  and enforcement actions common practice; (3) making data on design,  performance, costs, and benefits of green infrastructure known and  readily available; (4) decreasing the financial burden to communities of  installing and maintaining green infrastructure; and (5) establishing  partnerships and capacity building, where communities are networking  and exchanging information on the best green infrastructure approaches.  The goals most relevant to EPA’s providing assistance to municipalities to  employ green infrastructure are the latter three, providing information,  funding, and partnerships and capacity building.
To address the goal of making information available on the design,  performance, costs, and benefits of green infrastructure, EPA has  provided extensive information on its website, including sharing its own  research and that of academics, nonprofit groups, and other entities on a  variety of issues related to green infrastructure. For example, the website  contains links to documents and databases from EPA, universities, and  others on the performance and benefits of specific green infrastructure  technologies, such as a report summarizing results from research  conducted by EPA’s Office of Research and Development into the  performance of several green infrastructure practices. The website also  contains links to  technical webcasts for public officials and green infrastructure  practitioners concerning specific green infrastructure practices, such  as design, operation, and maintenance, including a webcast  addressing strategies on designing, implementing, and maintaining  green infrastructure at the local level and a webcast on the cost- savings and benefits of using green infrastructure, and  fact sheets and supplemental materials that EPA has developed to  provide examples of how green infrastructure can be incorporated into  permits and other compliance agreements, such as CSO consent  decrees.
In addition, since 2012 EPA has provided $2.8 million in technical  assistance to 52 municipalities for planning and implementing green  infrastructure. On the basis of this work, EPA has posted on its website  case studies focused on the use of green infrastructure options to  address a variety of site-specific issues related to green infrastructure,  such as flood mitigation, the capture of stormwater for reuse for irrigation  of parkland, adaptation to climate change, the integration of green  infrastructure into transportation planning, and addressing barriers to  using green infrastructure. For example, in one case study, EPA identified  green infrastructure options for a low-lying coastal area subject to sea  level rise. In another case study, EPA worked with a city to develop a conceptual design for a 100,000-gallon storage tank that the city will use  to harvest stormwater from a storm drain system, reducing runoff and  using the water to irrigate parkland. In addition, EPA also issued a  summary report to convey the overall lessons learned in the technical  assistance projects.
To address the goal of decreasing the financial burden to communities of  installing green infrastructure, EPA has provided funding for green  infrastructure to municipalities. For example, since 2009, the Green  Project Reserve (GPR), which is part of the agency’s Clean Water State  Revolving Fund, has provided $944 million for green infrastructure project  loans to municipalities, according to EPA’s website. Green infrastructure  projects funded under the GPR have included (1) urban reforestation in  one city that has served the dual purpose of reducing stormwater runoff  and promoting urban revitalization in an economically distressed area and  (2) in another city, a bioengineered stream and constructed wetland that  reduced stormwater runoff by enhancing water infiltration into the ground  while creating a public gathering space. EPA also provides funding under  other programs for green infrastructure, including through Clean Water  Act Nonpoint Source Grants and through its Urban Waters Small Grants  Program, Five Star and Urban Waters Restoration Grants Program, and  Greening America’s Communities Program, among others.
To address the goal of establishing partnerships and capacity, EPA  officials said that they held a series of national community summits to  encourage peer-to-peer exchange for better stormwater management  from 2013 to 2015. The agency now works with a network of  municipalities, which was created in 2015, focused on effectively using  green infrastructure. The network brings together green infrastructure  practitioners from different communities to help them learn from each  other as they use green infrastructure. In addition to collaborating with  this network, EPA developed a web application called the Green  Infrastructure Wizard to connect communities to EPA green infrastructure  tools and resources and maintains an electronic mailing list called  GreenStream to help share publications, training, and funding  opportunities. EPA officials said that they also sponsored efforts to  educate students in the use of green infrastructure. Since 2012, EPA has  held the Campus RainWorks Challenge, an annual competition for  college students, with the intention of exposing future engineers and  designers to green infrastructure concepts. In these challenges, college  students form teams, each with a faculty sponsor, and design innovative  green infrastructure projects for their campuses to effectively manage  stormwater. In 2016, according to EPA’s website, student teams from 30  states submitted designs that were judged by representatives from EPA  and its cooperating organizations—the American Society of Landscape  Architects, the American Society of Civil Engineers, and the Water  Environment Federation.
In 2016, EPA conducted an informal assessment of its progress in  advancing the use of green infrastructure and determined that the  information, assistance, and funding that the agency provided had not  resulted in communities institutionalizing green infrastructure in a similar  fashion to gray infrastructure. EPA officials we interviewed said that they  regarded the early years of the agency’s green infrastructure program as  an educational phase that increased awareness of the use of green  infrastructure in managing stormwater. However, these officials said that  they have found that while municipalities are now generally aware of  green infrastructure, they are not using it extensively to manage  stormwater, and the officials identified challenges for the municipalities in  installing green infrastructure. The officials said that fully integrating  stormwater management into other community planning efforts requires a  sufficiently long time horizon to help maximize environmental benefits and  provide cost efficiencies by synchronizing a community’s plans with its  stormwater management and any Clean Water Act obligations; this  horizon is likely longer than the current 5-year permit window and the  agency is exploring how to incorporate long-term planning approaches  into permit conditions. EPA officials said that while it is possible to  implement many practices on an ad hoc basis, comprehensive  implementation across a municipality’s stormwater area can take multiple  permit cycles. The EPA officials said that the agency would like  communities to be more easily able to integrate green infrastructure into  capital improvement plans and other municipal plans to realize the most  effective environmental benefits and cost savings. In addition, EPA  officials said that since green infrastructure is relatively new,  municipalities do not know if using green infrastructure will meet the  requirements of their permits and thus may be discouraged from using it.
To address these challenges to installing green infrastructure, EPA  officials said that they would develop a new focus on helping  municipalities find ways to incorporate green infrastructure into  stormwater systems over a longer period of time while still meeting permit  requirements. The officials said that beginning in 2016, they launched a  pilot project to work with 5 municipalities to develop long-term stormwater  plans that incorporate green infrastructure. The officials said that they  plan to work with these municipalities to identify projects to address  stormwater management, including meeting permit requirements, while  developing and implementing larger infrastructure and community plans  that address other needs, such as transportation or recreation. According  to EPA officials, the long-term stormwater plans will include projects that  will be implemented over the course of multiple permit cycles—perhaps  as long as 20 to 30 years. The long-term stormwater plans will be  incorporated into permits, to show how the permits’ requirements to limit  or eliminate stormwater pollution will be met. According to an EPA official,  a municipality’s long-term stormwater plan would be reevaluated when its  stormwater permit is renewed. EPA officials said that one purpose of the  pilot project will be to help integrate a municipality’s long-range  stormwater plan into its shorter-term permits.
EPA officials also said that the idea of the pilot project is to demonstrate  to other municipalities the benefits of using a long-term approach to  planning for green infrastructure and stormwater management. According  to the officials, this long-term approach can be more cost-effective for  municipalities installing green infrastructure and can help reduce the  costs of complying with permit requirements. More specifically, agency  officials we interviewed said that by incorporating stormwater  management at the same time as other infrastructure projects, such as  transportation projects, the costs of implementing green infrastructure  could be reduced while balancing other community priorities. For  example, a park that includes green infrastructure features, such as  bioswales, will serve two purposes, providing both recreational area and  stormwater drainage, and the costs to install permeable pavement are not  as high if the work is synchronized with other repaving projects, such as  adding bike lanes.
section_title: EPA Plans to Establish Five Collaborative Groups with Municipalities but Has Not Yet Developed Written Agreements on Collaborating with Them
paragraphs: EPA officials we interviewed said that through the pilot project, the  agency plans to establish groups in five municipalities to work  collaboratively on developing long-term stormwater plans. By working  with each municipality for at least 12 to 18 months, EPA officials said that  they intend for each municipality to form a group of stakeholders that will  collaborate to integrate green infrastructure into long-range plans that  may include other municipal infrastructure elements, such as parks or  streets. The participants for each of the five municipalities will include  EPA; its consultants; the municipal department responsible for  stormwater; potentially state NPDES permitting authorities; other  municipal departments, such as for roads or parks; interest groups; and  members of the general public. The participants may vary, depending on  the municipality and other potential infrastructure improvements the  municipality may be planning, and EPA officials said that they will work  with stormwater officials in each municipality to identify the appropriate  local agencies and other stakeholders that need to be involved in  developing the stormwater management plan.
The use of such a collaborative group is consistent with one of the  mechanisms to implement interagency collaborative efforts that we  identified in a 2012 report on key considerations for implementing  interagency collaborative mechanisms. That report discusses different  types of collaborative mechanisms, such as a coordinator appointed by  the President or an interagency task force. In that report, we also  identified that all collaborative mechanisms benefit from certain key  features, which raise issues to consider when implementing these  mechanisms. These issues are shown in table 1.
EPA officials said that they have agreements with each municipality that  the agency will provide each group with technical assistance. EPA  officials also said that they would provide $150,000 to each municipality,  for a total of $750,000 for the pilot. When we asked about what resources  or documents EPA would use to guide the pilot project and the work with  the five municipal groups, EPA officials referred us to the following  agency resources that provide guidance to communities and wastewater  utilities for planning for sustainability and managing stormwater planning  more generally.
Community Solutions for Stormwater Management: A Guide for  Voluntary Long-term Planning (2016). According to the guide, it  describes how to develop a comprehensive long-term community  stormwater plan that integrates stormwater management with a  municipality’s broader plans for economic development, infrastructure  investment, and environmental compliance. The document says that  when developing a plan, a community should determine and define  the scope of the integration effort, ensure the active participation of  entities that are needed to implement the plan, and identify the role  each entity will have in implementing the plan. EPA officials said that  this document outlines the approach they will use for the pilot projects.
EPA is also developing a web-based Toolkit that will include technical  and financing resources to walk communities through the long-term  stormwater planning process provided in the Community Solutions for  Stormwater Management guide   Integrated Municipal Stormwater and Wastewater Planning Approach  Framework (2012). According to the document, it is for use by EPA,  states, and local governments to develop and implement integrated  plans under the Clean Water Act. Steps for developing a plan include  defining the scope of the integration effort, ensuring participation of  the entities needed to implement the integrated plan, and identifying  the role each entity will have in implementing the plan. EPA officials  said that the pilot project’s approach to long-term planning reflects  EPA’s Integrated Planning Framework.
In addition, we identified other EPA resources which include some  features that we have identified as being helpful for collaborative groups.  These documents include the following information:
Green Infrastructure in Parks: A Guide to Collaboration, Funding, and  Community Engagement (2017). According to the guide, it is  intended to encourage partnerships between park agencies and  stormwater agencies aimed at promoting the use of green  infrastructure on park lands. It identifies steps to facilitate the  implementation of green infrastructure in parks, including identifying  and engaging stakeholders; building relationships; leveraging funding  opportunities; and undertaking high-visibility pilot projects, which it  says helps gain support for more green practices.
Planning for Sustainability: Handbook for Water and Wastewater  Utilities (2012). According to the handbook, it is intended to provide  information about how to enhance current planning processes by  building in sustainability considerations. It is designed to be useful for  various types and scales of planning efforts, such as long-range  integrated water resources planning. The steps include the utility  internally identifying sustainability priorities and potential opportunities  and engaging the community about its sustainability priorities.
Key to the success of the five groups is collaboration among the  participants as they develop their long-range stormwater plans. Although  EPA officials said that the documents they provided were not intended to  include how EPA, municipal departments, and other stakeholders are to  collaborate, they reflect some of the key considerations for implementing  interagency collaborative mechanisms that we identified in our past work.  For example, the two 2012 documents identify the need for appropriate  participants to be involved in a collaborative group, and the 2016  document discusses the need to identify the roles that each entity will  have in implementing a plan and to define the scope of the effort. In  addition, the 2017 park planning document states that identifying  opportunities to provide resources through leveraging funds can help  incorporate green infrastructure features into a park, while at the same  time accomplishing other purposes, such as providing trails and irrigation  for sports fields.
EPA officials we interviewed said that the efforts with the five municipal  groups have just started and that they have not developed further  guidance for how to collaborate with the municipalities and relevant  stakeholders. In particular, EPA officials said that the five groups have not  yet developed agreements on how they will work together to collaborate.  According to the officials, they are working on additional resources to  provide further details about options to engage communities, promote  accountability, prioritize goals and actions, and identify financing options.  Our prior work has found that agencies that articulate their agreements in  formal documents, such as memorandums of understanding, can  strengthen their commitment to working collaboratively. A written  document can incorporate agreements reached among participants in any  or all of the following areas: leadership, accountability, roles and  responsibilities, and resources. When working with the five groups in the  pilot project, EPA could better assure that they will successfully develop  long-term stormwater plans if they document their agreement on how they  will collaborate, such as in a memorandum of understanding, aligned with  our key considerations for implementing interagency collaborative  mechanisms. Similarly, any other efforts to develop long-term stormwater  plans after the pilot project would benefit from the groups documenting  their agreement on how they will collaborate.
section_title: Conclusions
paragraphs: In the last 10 years, EPA’s green infrastructure program has focused on  educating municipalities by providing information, technical assistance,  and funding and, as our survey results show, has helped municipalities  achieve familiarity with the general concept of green infrastructure. Yet  EPA officials we interviewed believe that they are now at a turning point in  this program, noting that green infrastructure is still not a prominent  component of most municipal stormwater programs. EPA’s pilot project  with five municipalities is a good way to focus on developing long-term  stormwater plans. However, the success of EPA’s pilot project—and any  other efforts to develop long-term stormwater plans after the pilot  project—depends on successful collaboration among wide-ranging  groups of participants. Our previous work on key considerations for  implementing interagency collaborative mechanisms, such as the  municipal groups proposed by EPA, provides more specific ways for  groups to work together than what is currently contained in EPA  documents. That work has also found that agencies that articulate their  agreements in formal documents, such as memorandums of  understanding, can strengthen their commitment to working  collaboratively. When working with the municipal departments and other  stakeholders, such as those in each of the five groups in the pilot project,  EPA could have a better assurance that the groups will successfully  develop long-term stormwater plans if they document their agreement on  how they will collaborate, such as in a memorandum of understanding,  aligned with our key considerations for implementing interagency  collaborative mechanisms.
section_title: Recommendation for Executive Action
paragraphs: The Director of EPA’s Office of Wastewater Management should, when  working with municipalities and other stakeholders to develop long-term  stormwater plans, document agreements on how they will collaborate,  such as in a memorandum of understanding, aligned with our key  considerations for implementing interagency collaborative mechanisms.  (Recommendation 1)
section_title: Agency Comments
paragraphs: We provided a draft of this report to EPA for review and comment. In its  written comments, reproduced in appendix III, EPA generally agreed with  our findings, conclusions, and recommendation. EPA stated that it is in  the early stages of the pilot project to assist municipalities in developing  long-term stormwater plans and will utilize the collaborative practices  recommended by GAO as it implements the project over the next 12 to 18  months. EPA’s plans, if implemented as described, would address our  recommendation. EPA also provided technical comments, which we  incorporated as appropriate.
As agreed with your office, unless you publicly announce the contents of  this report earlier, we plan no further distribution until 30 days from the  report date. At that time, we will send copies of this report to the  appropriate congressional committees; the Administrator of the  Environmental Protection Agency; the Director, Office of Management  and Budget; and other interested parties. In addition, this report will be  available at no charge on the GAO website at http://www.gao.gov.
If you or your staff members have any questions about this report, please  contact me at (202) 512-3841 or gomezj@gao.gov. Contact points for our  Offices of Congressional Relations and Public Affairs may be found on  the last page of this report. Key contributors to this report are listed in  appendix IV.
section_title: Appendix I: Objectives, Scope, and Methodology
paragraphs: In this report, we (1) describe to what extent selected municipalities are  incorporating green infrastructure into their efforts to comply with National  Pollutant Discharge Elimination System (NPDES) permits and consent  decrees that address combined sewer overflows (CSO), and what is  known about funding for such efforts; (2) describe what challenges, if any,  these municipalities reported facing to incorporate green infrastructure  into their efforts to comply with those permits and consent decrees; and  (3) examine efforts the Environmental Protection Agency (EPA) is taking  to help municipalities use green infrastructure.
To describe how selected municipalities are incorporating green  infrastructure into their efforts to comply with NPDES permits and consent  decrees that address CSOs, what is known about funding for such efforts,  and any challenges municipalities reported facing in incorporating green  infrastructure into these efforts, we conducted a survey of representatives  of 31 municipalities. We selected 20 municipalities that had NPDES  permits required of municipalities to discharge stormwater into nearby  water bodies, such as creeks, lakes, and rivers. The remaining 11  municipalities had entered into consent decrees with EPA to address  CSOs. We restricted our selection of the 31 municipalities to those in the  50 states and Washington, D.C. Although we selected these  municipalities at random from a range of geographic locations and a  range of sizes, our sample of 31 municipalities cannot be generalized to  all municipalities in the United States.
We randomly selected the 20 municipalities with NPDES permits from the  list of more than 5,000 municipalities that EPA identified in its 1999 rule  extending the NPDES program to smaller municipalities. By using the  1999 list, which is almost 18 years old, we enhanced the likelihood that  survey respondents would have experience conducting work to comply  with their permits. We stratified our sample by size and location.  Specifically, we randomly selected 10 municipalities with phase I  permits—generally required for municipalities with populations of 100,000  or more—from each of EPA’s 10 regions. We also randomly selected 10  municipalities with phase II permits—generally required for governmental  entities with populations of fewer than 100,000 from each of EPA’s 10  regions. Six of the selected municipalities were not available to participate  in our survey; in each case, we randomly selected a municipality with the  same type of permit from the same EPA region to take its place. Table 2  lists the 20 municipalities with permits that we surveyed, the EPA region  in which it is located, and the size of population it serves.
We randomly selected the 11 municipalities that have entered into  consent decrees with EPA to address CSOs from a list of 36 such  municipalities that EPA provided to us. These were municipalities that  entered into consent decrees to address CSOs after August 2007. August  2007 is the date of a memorandum in which EPA states, among other  things, that it will consider the feasibility of using green infrastructure in its  enforcement activities, for example, consent decrees that address  CSOs. An analysis of the 36 consent decrees showed that they differed  in two characteristics—about half had some mention of green  infrastructure in the text of the consent decree and about half were  entered into with municipalities in EPA’s Region 5 (the Great Lakes  region). The consent decrees were roughly distributed evenly among four  groups—with and without mention of green infrastructure and either in or  not in Region 5. We stratified our sample of 11 municipalities with consent  decrees to be proportionally representative of both of these  characteristics. In four instances, a municipality was not available to  participate in our survey, in which case we randomly selected another  municipality with similar characteristics. We selected these municipalities  at random from a range of geographic locations and a range of sizes;  however, because of the sample size, among other factors, the results  are not generalizable to all municipalities in the United States. Table 3  lists the 11 municipalities with CSO consent decrees that we surveyed,  the EPA region in which it is located, and population it serves.
The questions we asked municipalities in our survey focused on (1) the  extent to which the municipalities were using green infrastructure to  comply, at least in part, with requirements of their permits or consent  decrees; (2) the amount and source of capital expenditures for green  infrastructure to comply, at least in part, with requirements of their permits  or consent decrees; and (3) the challenges the municipalities may have  experienced in using or considering green infrastructure to comply, at  least in part, with requirements of their permits or consent decrees.
The time frames for which we asked for information from the survey  respondents varied by the questions we asked and whether a municipality  was included in our survey because it has an NPDES permit or a consent  decree to address CSOs. For questions to municipalities with permits  about the extent to which the municipalities were using green  infrastructure and questions about the challenges the municipalities may  have experienced in using or considering green infrastructure, we asked  for information for approximately the 5-year period prior to our survey. For  questions to municipalities with consent decrees, we did not specify a  time frame. For information on the amount and source of capital  expenditure for municipalities with permits and municipalities with consent  decrees, we asked survey respondents for the information from the  respondents’ last 3 completed fiscal years. We limited these questions to  3 fiscal years to reduce the work burden on the respondents.
Our survey questions about the extent to which the municipalities were  using green infrastructure included questions about each of the 11  examples of green infrastructure that EPA listed on its website. Our  survey questions about the amount and source of capital expenditures for  green infrastructure asked about the cost of green infrastructure that was  incurred by the permit holder. Seventeen respondents were able to  provide us with the information—some provided it during the survey, and  others provided it after we concluded the survey. In some instances, the  respondents indicated that the expenditure information was an estimate.
Our survey questions about challenges asked about the experiences the  municipalities had regarding eight aspects of infrastructure development  that may have posed challenges to them in using green infrastructure  compared to their experiences in using gray infrastructure. The eight  aspects are (1) obtaining land for the infrastructure project, (2) designing  and engineering the project, (3) developing estimates for capital  expenditures, (4) developing estimates for operation and maintenance  expenditures, (5) installing the project, (6) the overall cost of the project,  (7) confidence in the effectiveness of green infrastructure compared to  gray infrastructure, and (8) the political and public opinion of green  infrastructure compared to that of gray infrastructure.
For each of these eight aspects, we asked municipalities to describe  situations in which the aspect encouraged them to install green  infrastructure and situations in which the aspect discouraged them from  doing so. We examined each of the responses for each of the aspects to  identify broad themes, including being unfamiliar with green infrastructure  and being committed to using it. To identify the most common themes, we  conducted a content analysis in which one analyst classified each  response into one or more of the themes and a second analyst  independently verified these classifications. For each aspect, we also  asked municipalities if, in general, the aspect made green infrastructure  usually more challenging than gray infrastructure, usually less  challenging, or about the same.
We conducted the survey by telephone from November 2016 through  April 2017, with one analyst asking the questions, a second analyst  documenting the responses electronically, and usually a third analyst  taking handwritten notes. We reviewed the responses for accuracy and  electronically transferred them into an Excel spreadsheet for analysis. For  our survey, we used two questionnaires that were similar in content—one  was used with municipalities with NPDES permits and the other was used  with municipalities with CSO consent decrees. Both questionnaires are  presented in appendix II. To help formulate our survey questions, we  reviewed EPA documents and other literature describing green  infrastructure and how green infrastructure projects are developed. We  then met several times with a public interest group that represents  municipal utilities and is familiar with green infrastructure and stormwater.  We also pretested the survey with three municipalities and adjusted  questions to make them more clear and answerable, as appropriate.
To examine efforts EPA is taking to help municipalities use green  infrastructure, we reviewed EPA regulations, guidance, and reports, as  well as information and tools on EPA’s green infrastructure website. In  addition, we interviewed officials from EPA’s Office of Wastewater  Management about their ongoing and proposed efforts to encourage the  use of green infrastructure. Specifically, we interviewed them about  progress toward the items in the agency’s 2013 Strategic Agenda for  green infrastructure and efforts they have made to develop a pilot project  to collaborate with five communities to incorporate green infrastructure  into long-term infrastructure investment plans and permits. We used key  considerations on interagency collaboration identified in our prior work to  assess the guidance available to the agency to develop collaborative  groups. Specifically, our previous work identifies features of collaborative  groups, including defining outcomes and ways to track progress, clarifying  roles and responsibilities of participating agencies, ensuring that relevant  groups participate, and putting guidance and agreements in writing.
For all three objectives, we interviewed EPA officials in the agency’s  Office of Wastewater Management, the office responsible for managing  the Green Infrastructure Program, and Office of Enforcement and  Compliance Assurance, as well as representatives from several public  interest groups, about the use of green infrastructure by municipalities.
We conducted this performance audit from February 2016 to September  2017 in accordance with generally accepted government auditing  standards. Those standards require that we plan and perform the audit to  obtain sufficient, appropriate evidence to provide a reasonable basis for  our findings and conclusions based on our audit objectives. We believe  that the evidence obtained provides a reasonable basis for our findings  and conclusions based on our audit objectives.
section_title: Appendix II: Questionnaires Used in the Survey
paragraphs: GAO used two questionnaires that were similar in content to conduct the  survey of municipalities. One questionnaire was used for municipalities  with National Pollutant Discharge Elimination System (NPDES) permits,  and the other questionnaire was used for municipalities with consent  decrees that address combined sewer overflows (CSO). Both  questionnaires are presented below.
section_title: Appendix III: Comments from the Environmental Protection Agency
section_title: Appendix IV: GAO Contact and Staff Acknowledgments
subsections: section_title: GAO Contact
section_title: Staff Acknowledgments
paragraphs: In addition to the contact named above, Susan Iott (Assistant Director),  Rodney Bacigalupo, Mark Braza, John W. Delicath, Elizabeth M. Dretsch,  Charles Egan, Richard P. Johnson, Ilga Semeiks, and Sarah Veale made  key contributions to this report.