PURE POTENTIAL

The Case for Stormwater
Capture and Use

MARCH 2022


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Disclaimer

The information in this document was funded by the U.S. Environmental Protection Agency under Contract
68HERH19D0033. Mention of trade names or commercial products does not constitute endorsement or recommendation
for use. Furthermore, this document is a summary of the views of the individual convening participants; approval for
publication does not signify that the contents reflect the views of the Agency, and no official endorsement should be
inferred

Pure Potential: The Case for Stormwater Capture and Use

March 2022 •


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CONTENTS

A Call to Action: Notes from the Planning Team	5

Why Stormwater Capture and Use?	7

SCU Drivers and Benefits	7

The Case for a Co-Beneficial Design	8

SCU Potential	10

Strategic Framework for Capturing the Opportunity	11

1.	Advance the Nation's Commitment to SCU	13

Recommended Actions: Support and Develop the National SCU Community of Practice	13

Recommended Action: Develop More Detailed Estimates of SCU Potential and Implementation	13

2.	Build Trust, Understanding, and Partnerships	13

Recommended Action: Develop a Beginner's Guide to Help Stormwater Managers Get Started With SCU 14

Recommended Action: Develop Strategies for Effectively Communicating SCU Co-Benefits Using "Words
That Work"	14

Recommended Action: Develop Frameworks for Building Broader Partnerships in Support of Regional-Scale
SCU	15

WRAP Action 2.16:	15

Recommended Action: Analyze Challenges and Opportunities to Integrating Public and Private Investments
in SCU	16

3.	Expand Funding and Financing Mechanisms	17

Recommended Action: Evaluate and Publicize Methods for Characterizing and Monetizing the Co-Benefits
Associated with SCU	18

Recommended Action: Clarify Flow Existing Financing Mechanisms Can Be Used to Pay for SCU Projects.. 19

Recommended Action: Clarify and Share Innovative SCU Financing Solutions	20

Recommended Action: Assist Small and Underserved Communities in Accessing Funding Opportunities... 22

WRAP Action 8.5:	22

4.	Improve Regulations, Policy, and Guidance	22

Recommended Action: Develop a Compendium of NPDES Permitting Approaches for SCU Applications.... 22

Recommended Action: Clarify Flow States Regulate Stormwater Capture and Use	23

Recommended Action: Evaluate State Water Rights Constraints to SCU	25

5.	Advance Science and Treatment Standards	25

Recommended Action: Develop Guidance on Determining Treatment Standards for SCU Systems	26

Recommended Action: Bolster Research Pertaining to the Physical Science of SCU and Assessment of Urban
Stormwater Quality	27

6.	Accelerate the Use of New Technologies and SCU Strategies	28


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Recommended Action: Support Expansion of SCU Technology Validation Processes to Ease Regulatory
Acceptance	28

Recommended Action: Update Existing National Stormwater Practice Databases to Support Validation of
SCU System Performance	28

Recommended Action: Validate and Propagate Robust Sensing and Control Devices to Measure Water
Quantity and Quality in SCU Systems	29

Recommended Action: Identify Common SCU Technology Permutations to Enable Development of
Standardized Design Plans and Review Processes	29

Conclusion: Keys to Unlocking SCU Potential	30

Appendix A: Recommended Actions for Addressing SCU Needs	31

Building Trust, Understanding, and Partnerships	31

Funding Mechanisms	31

Regulations, Policy, and Guidance	32

Science and Treatment Standards	32

Technology Performance	33

Appendix B: Key SCU Research Needs	34

Building Trust, Understanding, and Partnerships	34

Funding Mechanisms	34

Regulations, Policy, and Guidance	34

Science and Treatment Standards	35

Technology Performance	35

Appendix C: Notes and References	36

Photo Credits	38

Appendix D: Acronyms	39

Pure Potential: The Case for Stormwater Capture and Use

March 2022 « 4


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A CALL TO ACTION: NOTES FROM THE PLANNING TEAM

As America's water managers embrace the challenges of climate change and associated risks to water supply, a distinct
focus to date has been on increasing supply through wastewater reuse and desalination. Increasingly, though, we are
recognizing the great potential to harvest, treat, and use stormwater and rainwater to address supply vulnerabilities,
improve water quality, reduce flooding risk, and achieve other co-benefits in urban areas. In some parts of the country, this
potential is being realized through successful implementation of both small- and large-scale projects to harvest stormwater
and rainwater for consumptive use. However, the understanding of stormwater capture and use (SCU) potential and
challenges varies across the nation, and many areas could benefit from the experience and insights of early SCU adopters
that have successfully implemented stormwater/rainwater harvesting projects. Interest in SCU is growing, but it is vital to
build a better understanding of how its drivers, potential, and implementation challenges vary across different scenarios in
order to effectively build our capacity to implement SCU across the nation.

To help increase awareness of SCU opportunities and build state and local capacity to pursue locally appropriate projects,
the U.S. Environmental Protection Agency (EPA), National Municipal Stormwater Alliance, WateReuse Association, Water
Environment Federation, and the Re-Inventing the Nation's Urban Water Infrastructure (ReNUWIt) research consortium
organized five national webcasts and meetings in 2021 that culminated in an intensive national convening to explore these
opportunities and challenges and identify priority actions to advance SCU in urban areas across the nation. The webcasts
and web-based meetings gathered national experts in stormwater management to discuss SCU drivers, stormwater
treatment standards, an evaluation of the co-benefits that SCU projects generate, and estimations of SCU potential.
Building on this groundwork, a diverse group of national stormwater experts and thought leaders met in September 2021
at The Johnson Foundation at Wingspread to identify the highest priorities for building financial, regulatory, scientific,
technical, and organizational capacity to pursue SCU while placing it within the broader context of integrated urban water
management. Participants recognized that interest in and experience with SCU vary widely around the country, and that
different practitioners will need different types of support depending upon local water management circumstances. Most
importantly, the group concluded that SCU and integrated stormwater management must be a critical tool in the portfolio
of options for promoting the design and management of resilient water management systems in urban communities.

This report lays the groundwork for establishing a unified community of practice around SCU and a strategic framework for
coordinated action to address the most important challenges to widespread SCU implementation in urban areas. Where
practicable, the report assigns specific organizations to lead key actions for helping stormwater managers build familiarity
with effective SCU practices and developing local capacity for SCU implementation. The WRAP provides a vehicle for
collaboration and onboarding of new actions focused on enabling consideration of SCU practices. Initial conversations have
clarified a path forward for addressing SCU challenges and stakeholder groups have begun to act. There is no better time
than now to leverage the national interest in SCU and the co-benefits these projects can provide. The authors hope that
this report will serve as a resource to inform stormwater managers across the country about the benefits of SCU
approaches, catalyze action, and stimulate a broader dialogue about how SCU fits within integrated water management
approaches to become a critical component in broader strategies to advance a resilient water future.

Sincerely,

Pure Potential: The Case for Stormwater Capture and Use

A Call to Action: Notes from the Planning Team «




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Dave Smith

Principal
Water Innovation Services
(Formerly With U.S. EPA Region IX)

Aiiza Furneaux

Technical and Regulatory Programs Director
WateReuse Association

^WateReuse

Wafer Innovation
Services

Seth Brown

Executive Director
National Municipal Stormwater Alliance

Richard Luthy

Director

Re-Inventing the Nation's Urban Water Infrastructure

ReNUWIt

Ifw NWion'j

URBAN WATER
INFRASTRUCTURE

Claudio Ternieden

Senior Director of Government Affairs & Strategic Partnerships
Water Environment Federation

Water Environment
Federation*

the water quality people*

Danielle Johnson

Senior Program Associate
The Johnson Foundation

Johnson

Foundation

AT WINGSPREAD

Justin Mattingly

Water Reuse Team
U.S. EPA

SEPA

Pure Potential: The Case for Stormwater Capture and Use

A Call to Action: Notes from the Planning Team •


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WHY STORMWATER CAPTURE AND USE?

SCU Drivers and Benefits

SCU, whether at an onsite, community, or watershed scale, offers
an adaptive, multi-benefit approach to stormwater management
that can create long-term, positive outcomes and contribute to
the development of sustainable and climate-resilient
communities. Recognizing that the opportunities and challenges
associated with urban SCU are different than those associated
with rural stormwater management, this report principally
focuses on urban applications. A diverse range of drivers and
benefits have fueled increasing interest in urban SCU, including
water supply augmentation, water resilience, flood control,
pollution control, community enhancement, and environmental
benefits (see Figure 1 below).

The opportunities for SCU projects vary across the United States
based on geography, climate, and project scale. For example,
drivers for onsite and building-scale SCU are extremely localized
and based on the values, resources, and conditions of
infrastructure in a community (National Blue Ribbon Commission
for Onsite Non-Potable Water Systems [NBRC for ONWS], 2018).

Larger scale projects and projects in water-scarce regions tend to
be motivated principally by a mix of water quality management
and water supply/resilience interests, whereas SCU projects in
water-rich regions are typically implemented principally for flood
control and water quality purposes (e.g., regulatory compliance).

Stormwater managers across the United States have made
significant progress in implementing a wide range of SCU projects
contributing to the country's water reuse landscape, but there
have been no comprehensive efforts to build national or regional
capacity to capture and use stormwater until now. A more
intentional and systematic approach to SCU implementation that
aligns with other water management tools and is tailored based on local needs and interests would help accelerate
solutions to water supply challenges, improve resources available to communities, and advance environmental and public
health imperatives.

Applying Lessons Learned from Onsite Non-Potable Water Systems:

Beginning in 2014, the NBRC for ONWS has committed to accelerating the development of ONWS through policy
developments and applied science. To inform regulatory development for onsite reuse, the NBRC developed A
Guidebook for Developing and Implementing Regulations for Onsite Non-Potable Water Systems. The document provides
guidance for states and local jurisdictions on developing and implementing regulations and oversight programs for
ONWS using the risk-based framework that the NBRC supported (Water Environment & Reuse Foundation, 2017). The
purpose of the guidebook is to establish a consistent national approach for regulation and management of ONWS. It is
intended for use by state and local public health regulators seeking guidance on establishing water quality criteria for
ONWS. In addition to the guidebook, the NBRC for ONWS also developed template state legislation for establishing
regulatory programs for onsite non-potable water systems.

Building off the guidebook and template state legislation, the NBRC is developing an operator certification program,
planning approaches, and decision support tools to support the implementation of ONWS that are protective of public
health. EPA has assisted in this effort by conducting research in risk assessment and through the development of the
"Non-Potable Environmental and Economic Water Reuse" (NEWR) decision support tool to quantify the availability of

Pure Potential: The Case for Stormwater Capture and Use	Why Stormwater Capture and Use? • 7

What Is SCU?

SCU is the management practice of collecting and
using stormwater (water from precipitation runoff
that reaches the ground), rainwater (precipitation
that falls on roofs and is collected before reaching
the ground, streets, and other impervious surfaces),
and water in storm drain systems to achieve multiple
co-benefits. Captured stormwater and rainwater can
serve potable uses, such as aquifer recharge, as well
as a wide range of non-potable uses, including
irrigation, industrial supply, toilet flushing, washing,
dust suppression, firefighting, and evaporative
cooling, although treatment may be needed for
some uses. SCU can be referred to as "stormwater
harvesting" and may require storage and/or
treatment before use, depending on the application.
SCU practices are implemented at variable scales—
from building to watershed—and designed to collect
and store watershed-wide runoff during dry or wet
weather conditions. Project examples are included in
text boxes throughout this report to highlight various
urban SCU approaches.

SCU and other terms as they are described here are
only for the purposes of this report and are not
intended to represent official definitions. While SCU
can be a form of onsite reuse, this report is not
focused on building-scale SCU due to the past and
future work being completed by the NBRC for ONWS
(see textbox on page 4, below).


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alternative water sources—including rainwater—for building-scale reuse. The NBRC is continuing their work as part of
WRAP Action 3.4 (Develop Research and Tools to Support the Implementation of Onsite Non-Potable Water Reuse
Systems).

Furthermore, work is underway through WRAP Action 2.18 (Incorporate Water Quality and Onsite Reuse into Premise
Plumbing Codes and Standards) to incorporate water quality research on onsite water treatment, storage, and delivery
into building plumbing codes and standards at the national level, which local jurisdictions may then adopt. Local codes
and requirements vary substantially across communities, and local expectations for onsite reuse are not clearly
established in many jurisdictions. The objectives of this action include clarifying treatment targets for manufacturers of
onsite treatment technologies to spur innovation in the marketplace and help ensure that the latest science and risk-
based framework treatment benchmarks are incorporated into plumbing codes and standards to safely advance ONWS.

Seeing the potential benefit of ONWS, the city of Austin, Texas, passed ordinance updates in late 2021 requiring new,
large commercial developments to tap into onsite water resources. Following the ordinance updates, developments
submitting site plans must include a water benchmarking application, while large developments greater than 250,000
square feet in size will need to consult with Austin Water to discuss water efficiency requirements and incentives for
alternative water use. In 2023, any development over 250,000 square feet requiring a site plan will be required to build
an onsite water reuse system. City staff are monitoring the potential increases in housing costs that would be imposed
by these requirements.

Because harvested rainwater and stormwater are among the primary sources of water for ONWS, there are a lot of
synergies with broader SCU practices. The risk-based framework increasingly being used for ONWS can be adapted for
SCU, while the operator certification program currently under development in WRAP Action 3.4 will help inform
operational practices for SCU. For progress to continue on SCU, stormwater managers can look to the experiences in
onsite reuse and gain valuable lessons on policy development, O&M, and applied science.

The Case for a Co-Beneficial Design

SCU projects providing multiple co-benefits beyond primary drivers can effectively address the interests of a range of
stakeholders within a community or watershed, making the projects appealing to decisionmakers and stakeholders whose
interests they serve when properly designed to meet local needs. Figure 1 contains a summary of many of the potential
uses of harvested stormwater and the benefits those uses can provide. Evaluating and framing the full range of SCU co-
benefits and tailoring the messaging to be sensitive to specific stakeholder and decisionmaker audiences are crucial to
gaining support for expanding SCU capacity. Creating co-benefits also helps meet the needs of smaller or underserved
communities (e.g., by creating jobs, reducing costs, and providing an alternative source of water). By engaging broad
community interests early in project planning, SCU project developers can more effectively identify and integrate the
interests of underserved populations in project design.

Like other new water supply sources, SCU projects can be relatively expensive to implement, particularly when compared
to the average costs of existing water supplies and especially when project co-benefits are not considered. SCU project
costs are highly variable and depend upon project size and design, the intended use of the captured stormwater, regulatory
requirements, and other local conditions, such as siting constraints. SCU project costs tend to grow as treatment needs
become more complex and constructed storage becomes necessary. Larger-scale SCU projects may offer lower unit costs
(costs per volume of water provided) than smaller-scale projects. Several studies have found that SCU costs are similar to—
or lower than—the costs of many alternative approaches for augmenting water supply, like wastewater recycling and
seawater desalination (Cooley and Phurisamban, 2016; Southern California Water Coalition, 2018). New, conventional
water supply augmentation projects (e.g., new storage reservoirs and groundwater pumping) are becoming less feasible
due to limits of supply and environmental impacts (Gleick and Cooley, 2021). When factoring in various co-benefits from
stormwater capture and use, SCU is becoming increasingly cost-competitive with traditional supply options (Dirringer et al.,
2021). Moreover, when the value of environmental and community co-benefits of SCU projects is factored into
assessments of their costs and benefits, SCU projects are often even more attractive than alternative supply augmentation
approaches.

Pure Potential: The Case for Stormwater Capture and Use

Why Stormwater Capture and Use? • 8


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Lake Lawne Stormwater Reuse Facility, Orlando, Florida:

This multi-benefit project captures stormwater to supply non-
potable water for landscape irrigation, reduce nutrient pollution,
enhance park amenities, and improve habitat biodiversity.
Conveyances to drainage canals collect stormwater from the
residential, commercial, and industrial properties surrounding Lake
Lawne. The Lake Lawne Stormwater Reuse Facility implements the
converted canal system to impound untreated stormwater
previously discharged directly Into Lake Lawne and use the captured
stormwater to irrigate adjacent greenspaces (Orange County
Environmental Protection Division, 2019). Designing the project to
provide co-benefits, including compliance with a 2008 Total
Maximum Daily Load (TMDL) for nutrient pollutant loading to Lake
Lawne, increased the attractiveness of the project to the public and
local leaders and enabled the county to secure funding from
multiple, diverse sources.

Aerial view of the Lake Lawne Stormwater
Reuse Facility, which uses captured stormwater
to irrigate adjacent greenspaces.

Figure 1: Urban SCU Drivers and Benefits

Pure Potential: The Case for Stormwater Capture and Use

Why Stormwater Capture and Use? •


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SCU POTENTIAL

As shown in Figure 2, the amount of urban stormwater potentially available for capture and use is about the same as the
volume of treated municipal wastewater available for reuse and could yield enough supply to meet approximately three-
quarters of total public supply withdrawals (Aguilar & Brown, 2020; EPA, 2004; Dieter et al., 2018). For the purposes of
Figure 2, public supply withdrawals account for water withdrawn by public and private water suppliers that furnish water to
at least 25 people or have a minimum of 15 connections. Public suppliers provide water for a variety of uses, such as
domestic, commercial, industrial, thermoelectric-power, and public water use. Although more detailed estimates of SCU
potential are needed at the local level, it is clear that stormwater harvesting could help meet local water needs. A national
estimate of urban stormwater runoff that is currently being captured and used has not yet been developed; however, there
is room to expand the practice of SCU. One recent analysis suggests less than 7 percent of municipal wastewater flows are
being reused nationally (Rauch-Williams et al., 2018), and the portion of stormwater currently being harvested is estimated
to be much less. Even though large amounts of stormwater are available for capture, the true volumes of stormwater
available for capture are based on local factors, such as precipitation patterns, facility siting and treatment criteria, cost,
local needs, and the capacity to store captured stormwater.

Figure 2: How Much Can Stormwater Capture Augment Supplies in the United States?

50
45
40

Urban Stormwater Capture Potential Wastewater Reuse Potential	Public Supply Withdrawals (2015)



Aguilar & Brown (2020) and

EPA (2004) and EPA (2016)

Total public supply withdrawals in
2015
(Dieter et al., 2018)

Sources

EPA (2004)

(from EPA CWNS)

Understanding the opportunity for SCU at smaller geographical scales is important for raising awareness when
communicating with public and private stakeholders and decisionmakers; establishing water management goals at the
local, state, and regional levels; and developing tools/incentives to help promote SCU and the associated co-benefits.
Quantifying the amount of stormwater that can be captured can help link SCU with other sustainable planning efforts-
such as climate resiliency—and promote integrated water management strategies by fostering collaboration between
stormwater/watershed planning groups and water and sanitation districts looking for alternative water supplies. Such
collaborations can unlock additional resources for SCU implementation. The "Advance the Nation's Commitment to SCU"
section below recommends an action to develop more detailed estimates of SCU potential and implementation to better
enable water resource managers to incorporate SCU into planning decisions.


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Estimating SCU Potential Across Different Scales:

Researchers have applied several methods for estimating SCU potential at state, regional, and local scales to account for
unique geographic characteristics and site-specific planning and design needs. Methodologies applied at larger scales
provide snapshots of overall benefits and help inform or incentivize policy decisions. These methodologies use readily
available data on precipitation, land perviousness, and assumptions on the amount of runoff that is realistically available
for capture and use. SCU potential estimates at the watershed, neighborhood, or parcel scale require greater use of local
stormwater characteristics, patterns, land use constraints, and surface or aquifer storage capacity to get accurate results
(Garrison, et al., 2014; Fassman-Beck et al., 2020; Cooley, et al., 2022).

Time scales are an important consideration for SCU estimates, as volume can fluctuate significantly on a seasonal basis.
A "common currency" or consistent metrics that track annual, seasonal, and storm-specific capacity can help stormwater
managers communicate with various entities that can benefit from SCU projects.

STRATEGIC FRAMEWORK FOR CAPTURING THE
OPPORTUNITY

Although estimating the volumetric potential for SCU can be useful in goal setting and communicating with decisionmakers,
the motivation to pursue SCU solutions will not be based on capture potential alone. The ability to harness the full potential
of this variable resource and implement SCU practices on a widespread scale requires an adaptive framework to tailor SCU
approaches to address varying community needs while considering unique local circumstances and challenges. This
framework should be developed to consider differences in local stormwater and development characteristics,
environmental conditions, funding opportunities, regulatory constraints, public priorities and attitudes, and relationships
between involved organizations and agencies. All actions should support community capacity to design and implement SCU
projects that significantly aid in solving multiple communities' most pressing water management challenges at a time. The
remaining sections of this report outline a strategic framework for the following priority elements. A comprehensive list of
action recommendations, including possible lead organizations and timelines for completion, is included as "Appendix A" to
this report. The recommended strategic framework has six main goal elements:

1.	Advance the Nation's Commitment to SCU. Overarching leadership and communication are needed to further
develop the nation's awareness of SCU potential and capabilities to increase SCU implementation. Building the
nation's collective capacity through national-scale collaboration and information sharing will more efficiently
enable practitioners to take advantage of the promise of SCU. EPA, state agencies, local stormwater managers,
national organizations, researchers, consultants, and stakeholders need to take action to support and enable the
emerging SCU community of practice.

2.	Build Trust and Understanding Through Partnerships. SCU projects will ultimately be unsuccessful if they are
designed and implemented within a stormwater silo. Competing organizational perspectives and a lack of
understanding about SCU among drinking water, wastewater, and stormwater management agencies, in addition
to other state and local agencies (e.g., departments of transportation, planning, zoning, fish and wildlife), make it
difficult to incorporate SCU and, more broadly, stormwater management into locally integrated water
management frameworks. These management agencies may not have a unified view about the value of SCU, and
some may see SCU as being at odds with existing programs and utility operations. Realizing the full extent of
community benefits that SCU can provide requires a partnership approach, and the promise of co-benefits can
create opportunities for stormwater managers to collaborate with managers from other water enterprises, staff
from other areas of government, private sector representatives, and public stakeholders. New and innovative
communication approaches and tools are needed to better prepare stormwater managers to engage non-
technical public decisionmakers and build support with fellow water managers and community stakeholder
audiences to achieve support for SCU projects.

3.	Expand Funding Mechanisms. Municipal stormwater programs tend to be underfunded compared to wastewater
and drinking water programs and often have difficulty raising new funds, particularly when no dedicated revenue
stream exists. Although water is considered "cheap," SCU costs compare favorably with alternative methods of

Pure Potential: The Case for Stormwater Capture and Use

Strategic Framework for Capturing the Opportunity • 11


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new water supply, and the relative cost effectiveness will likely continue to increase, particularly in arid climates
(Luthy et al., 2019). Moreover, SCU projects are even more cost effective when the full range of co-benefits is
considered. To address the perceived funding challenges for building SCU capacity, stormwater managers will
need to define and persuasively communicate the economic case for implementing SCU projects and develop
innovative strategies for leveraging federal, state, and private funding opportunities. Furthermore, stormwater
managers may need to shift their perspectives and treat all scales of SCU as capital infrastructure projects on par
with conventional systems to unlock capital funding mechanisms.

Clarify Regulations, Policy, and Guidance. While there are no federal regulations specific to stormwater capture
and use, existing regulatory structures that may impact SCU include National Pollutant Discharge Elimination
System (NPDES) permitting, state water rights, state water reuse rules, and local codes. These regulatory
structures can create both barriers to and incentives for pursuing SCU. Federal, state, and local regulations can
help build capacity for SCU planning and implementation by setting stormwater management targets and
creating regulatory certainty to drive innovation. In many cases, the absence of regulatory drivers and certainty
makes it more difficult for engineers and water managers to incorporate SCU into building- and watershed-scale
planning. For example, uncertainty about whether new SCU technologies and strategies will be acceptable to
regulators likely inhibits their use.

Advance Science and Treatment Standards. Treatment standards that are protective of public and ecosystem
health and appropriate for designated uses are needed to ensure safe and affordable use of captured
stormwater. Developing methodologies for determining fit-for-purpose treatment standards and water quality
benchmarks for captured stormwater is complicated
because different uses require different levels of
treatment depending on human and aquatic life
exposures (e.g., to address indirect exposure from non-
potable uses, direct exposure to drinking water or food
sources irrigated with stormwater, or ecosystem
exposures where captured stormwater augments
wetlands and streamflow). Treatment standards also
need to account for varying pollutants present in
stormwater in different locations due to variations in
land use, seasonal differences in quality, and other
unique local conditions. Methodologies for determining
fit-for-purpose treatment standards for SCU ultimately
rely on urban stormwater quantity, quality, and
treatment performance data, which is often limited
and not fully representative of local conditions.

Ongoing work to tailor treatment standards to the
different combinations of target uses and stormwater
characteristics is needed to find the right balance
between protection and affordability, inform better
regulations, and build public confidence in the nation's
capacity to safely use harvested stormwater.

Accelerate the Use of New Technologies and SCU Strategies. Testing and validating the effectiveness of
measurement, control, and treatment technologies and practices applied to SCU solutions will ensure current
and future SCU projects are adequately protecting public and ecosystem health. Limitations in currently available
data on the effectiveness of SCU in removing pollutants and capturing flow hamper application and acceptance
of SCU practices. Understanding of the performance of SCU technologies and practices also varies, as access to
objective testing and validation programs/processes is limited and evaluation of effectiveness in different settings
remains uneven. These issues are particularly acute in regard to real-time sensing and controls, which hold great
promise in SCU applications but are not widely applied to stormwater infrastructure, in part because
practitioners and regulators lack sufficient understanding of their reliability and cost effectiveness.

Addressing SCU Research Priorities:

Under WRAP Action 7.2 and the effort to develop a
coordinated national water reuse research strategy,
The Water Research Foundation (WRF) "Project
4841: Assessing the State of Knowledge and
Research Needs for Stormwater Harvesting" seeks
to develop recommendations for stormwater
harvesting projects and associated research needs
based on an understanding of stormwater
harvesting practices at local, regional, and state
levels. To inform WRF Project 4841 and the broader
national water reuse research strategy, "Appendix
B" in this report contains a list of key research
needs for addressing communication, financial,
legal/regulatory, stormwater quality, technology,
and organizational challenges to advancing
consideration of SCU. The following sections of this
report identify research needs that rise to the level
of a priority action.

Pure Potential: The Case for Stormwater Capture and Use

Strategic Framework for Capturing the Opportunity • 12


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1. Advance the Nation's Commitment to SCU

In addition to actions that address specific challenges, there is a need for overarching leadership and communication to
build awareness of SCU opportunities among water managers at the federal, state, and local levels and among consultants,
engineers, citizen groups, and researchers. Broader-scale actions should be taken to help meet this need and create
ongoing mechanisms for coordination and information sharing.

Recommended Actions: Support and Develop the National SCU Community of Practice

1.	EPA intends to explore establishing an internal leadership caucus to spread awareness of outputs and initiatives
arising through this strategic action plan. Further engagement with Regional Water Division Directors and Office
Directors within EPA's Office of Water will help bring SCU to the forefront of stormwater management
conversations at the federal level and further support regional, state, and local SCU advancements. The group
should also consider how SCU fits within the broader set of policies, programs, and investments EPA implements
to advance stormwater management, effectively address key stormwater management, and integrate
stormwater management into other water management sectors. EPA should also introduce SCU opportunities
and needs into discussions with fellow federal agencies on water management responsibilities to help take
advantage of resources, regulatory coordination, and support that other agencies can provide (e.g., the U.S. Fish
and Wildlife Service, Bureau of Reclamation, U.S. Department of Agriculture Rural Development, Department of
Energy, and the Federal Emergency Management Agency [FEMA]). Federal interagency coordination on SCU fits
squarely within the role of the Water Reuse Interagency Working Group that was formally established by the
Bipartisan Infrastructure Law (BIL) to advance water reuse across the United States (BIL Section 50218).

2.	The national discussions of SCU opportunities and challenges over the past two years have revealed great
interest across the nation in further developing the community of practice focusing on SCU implementation. The
National Municipal Stormwater Alliance (NMSA), the WateReuse Association (WateReuse), the Water
Environment Federation (WEF), WRF, and EPA should continue building a vibrant community of practice by
seeking opportunities to showcase SCU successes and issues in national meetings of stormwater and water
recycling practitioners, regulators, funders, and researchers and by creating additional training opportunities to
help build technical capacity in specific areas of need.

3.	As the drivers for SCU vary significantly in different regions of the country, building capacity for coordination and
information sharing at regional levels would accelerate tailored approaches that are responsive to different SCU
drivers and interests. To complement cross-cutting actions at the national and regional levels, practitioners
should advance local and watershed-scale SCU visioning and planning to build understanding and commitment to
developing SCU capacity.

Recommended Action: Develop More Detailed Estimates of SCU Potential and Implementation
Developing and applying more robust SCU estimation methods at national and regional scales will enable water resource
managers to more easily make SCU assessments and decisions on the extent to which SCU should be incorporated into
water resource planning and investments. EPA and national research organizations should invest in creating replicable
methods for evaluating SCU potential, develop specific estimates at national and state scales, and widely share these
estimates with water resource managers across the nation. These methods can also be used to derive local, watershed, and
smaller-scale estimates to assist in specific community and project planning efforts. To complement and validate estimates
of SCU opportunity, national stormwater organizations (e.g., NMSA, WEF) and interested states (e.g., California) should
develop metrics (e.g., volume of water harvested) for tracking implemented stormwater capture projects and incorporating
comparable measures of stormwater volumes being captured and used. Together, improved methods for estimating SCU
potential and actual implementation can be used to highlight the opportunities to augment supply through harvesting and
enable measurement of SCU contributions to water supplies over time.

2. Build Trust, Understanding, and Partnerships

Recognizing and communicating the multiple co-benefits that SCU systems provide is critical to fostering water sector
partnerships and collaboration on SCU projects. To realize the full extent of SCU co-benefits, water managers will need to
collaborate outside of the typical enterprise silos (e.g., drinking water, wastewater, and stormwater) and effectively
communicate with non-technical public and private stakeholders. The following priority actions will help stormwater

Pure Potential: The Case for Stormwater Capture and Use

Strategic Framework for Capturing the Opportunity • 13


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managers more effectively communicate to build understanding of SCU with water agencies, the private sector, political
leaders, and public stakeholders. Building understanding will also help develop trust in a community's ability to harvest
stormwater and generate the multiple co-benefits these projects can safely and efficiently achieve. As stormwater
managers are at different stages of awareness about SCU possibilities, action is needed to help "beginners" get started in
evaluating and implementing SCU opportunities in their communities. Other communities will need more advanced help in
Improving communication strategies and skills needed to successfully build community support for SCU programs.

Recommended Action: Develop a Beginner's Guide to Help
Stormwater Managers Get Started With SCU

Many stormwater program managers are interested in, but unfamiliar with,
the details about SCU opportunity and key steps in developing effective
SCU projects and programs. EPA should partner with NMSA, WateReuse,
and other organizations to develop a guide to getting started with SCU
implementation. The guide will help practitioners evaluate SCU potential
within specific communities, taking into account local stormwater and
community characteristics, water management needs and goals, and
community priorities. This resource will introduce stormwater managers to
the range of SCU projects currently being implemented throughout the
United States, illustrating the differences between centralized and
decentralized projects and projects designed to supply potable and non-
potable uses. A training curriculum should be developed with the guide
that covers the basic features of SCU and other resources available to help
stormwater managers get started (e.g., communication strategies and
financing opportunities).

Recommended Action: Develop Strategies for Effectively
Communicating SCU Co-Benefits Using "Words That Work"
Communicating the co-benefits of SCU projects in a manner that
stakeholders understand and resonate with is an important step in
designing projects that address community needs and a mechanism for
building understanding and support for the project. Diverse tools can be
tapped to engage stakeholders (e.g., social media, webcasts, etc.) and
possible partners; however, successfully developing the proper message
and identifying the right target audiences are key to success.

Determining the proper terminology to describe SCU in a way that
resonates with public stakeholders and garners acceptance is a critical first
step in developing SCU communication strategies. Terminology studies
have been completed at local scales; however, a coordinated effort to
identify effective language for stormwater and stormwater management
approaches will help to build a common language and understanding.
Investigating the terms that public stakeholders commonly use to describe
SCU processes can help stormwater managers communicate effectively and
build trust across the community. Compiling and disseminating these
"words that work" will help SCU adopters effectively communicate SCU co-
benefits across water enterprises and engage non-technical public and
private stakeholders in the design of and support for projects. Equally
important, stormwater managers need to find the right points of
intersection with fellow agencies and present collaboration opportunities in
ways that resonate with the other agencies' priorities and points of view.

Helping Practitioners Communicate
Effectively:

Several existing resources identify
language choices that enable more
effective communications about SCU,
such as Water Reuse Context &
Terminology (WateReuse.org), Talking
About Water: Vocabulary and Images
that Support Informed Decisions about
Water Recycling and Desalination
(WateReuse.org), and What Is Green
Infrastructure? A Study of Definitions in
U.S. City Planning.

The Power of Plain Language:

Following an evaluation of stormwater
control implementation, New York City
changed how it described these projects
to avoid jargon and use plan language.
For example, "bioswales" became "rain
gardens."' These changes increased
understanding and support for these
management practices within the
community.

A rain garden constructed along the side of a
New York City street.

Providing stormwater managers with training programs focused on communication and stakeholder engagement strategies
can equip managers with ski I Isets needed to successfully engage with non-technical decisionmakers and stakeholders
throughout the SCU project development process to develop community support for SCU program implementation. For
instance, helping stormwater managers understand how an audience will process data based on their level of interest and

Pure Potential: The Case for Stormwater Capture and Use

Strategic Framework for Capturing the Opportunity • 14


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influence in a topic can lead to more effective engagement with peers and stakeholders (see Figure 3 below). Training
programs can also help stormwater managers identify the right agency partners and connect with them in ways that appeal
to other agencies' interests and priorities.

Figure 3: Stakeholder Mapping: Influence vs. Interest

Influence

Understand

Engage

^Interest

Monitor

Consult

How an audience will process data is linked to their interest and influence associated with a topic. Mapping the level of stakeholder
interest and influence will help stormwater managers determine whether to monitor (low interest, low influence), understand (low
interest, high influence), consult (high interest, low influence) or engage (high interest, high influence) a particular audience.

Recommended Action: Develop Frameworks for Building Broader Partnerships in Support of Regional-
Scale SCU

Effective partnerships are accomplished by engaging the right audiences and organizations at the right stages in project
development, including motivating, planning, building, operating, and decommissioning SCU systems. For example, water
agencies may partner with agencies in neighboring communities, other water sector managers within the community, and
non-governmental organizations during the planning and design phases of an SCU project that can provide project benefits
to each community, department, and partner group. When searching for opportunities to finance SCU projects, stormwater
managers may need to communicate with non-technical decisionmakers to build support. Once the project can be funded,
it is important for stormwater managers to break out of their "comfort zones" and collaborate with partners that they may
not be used to engaging with. Assessing opportunities and developing recommendations for creating interagency
agreements and publicizing legal frameworks for cross-program collaboration will enable stormwater managers to
successfully communicate across a diverse set of partners and implement regional-scale SCU projects.

WRAP Action 2.16

WRAP Action 2.16 seeks to identify institutional challenges to water reuse, assess opportunities for interagency
collaboration, and identify agreements and other legal models that support implementation of water reuse and other
integrated water management projects among "water cycle" utilities. The report Multi-Agency Water Reuse Programs:
Lessons for Successful Collaboration (March 2022) demonstrates how utility managers and other stakeholders can
resolve challenges and select appropriate legal models to lead successful, interjurisdictional water reuse programs.

Pure Potential: The Case for Stormwater Capture and Use

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Partnering to Capture Dry Weather Flow in Orange County, California:

Urban storm drains often carry water during dry periods due to runoff from excessive irrigation, car washing, and other
activities. Given the drought-driven need to diversify water supplies, municipalities and special districts in Orange
County, California, are increasingly viewing stormwater as a potential resource rather than a regulatory liability:. The
County of Orange and Orange County Flood Control District are working with three wastewater and water districts to
develop comprehensive stormwater capture opportunity studies to identify synergies between the stormwater and
flood control system and treatment/transport/recycling capacity on a service area-wide basis. The goal is to develop
comprehensive systems of diversions to capture and divert dry weather flows to the sanitary system to augment
recycled water supplies. While diversions were originally used to address site-specific surface water quality issues, the
evolution of water needs is setting the stage for their use in regional water supply planning and the conversion of a
liability into a resource.

Recommended Action: Analyze Challenges and Opportunities to Integrating Public and Private
Investments in SCU

Privately owned land makes up a significant portion of available land
in urban settings and therefore represents significant opportunity for
stormwater capture. However, construction, operation, and
maintenance of SCU systems on private property can be more costly
than conventional water systems. If landowners and businesses are
not required to implement stormwater management measures
during new development or redevelopment (per local post-
construction regulations), then the additional cost of an SCU system
can discourage these landowners and businesses from pursuing SCU.

One strategy for overcoming this challenge is implementing utility
incentives or rebates to encourage voluntary retrofits. Furthermore,
private landowners and businesses may not have the technical
expertise needed to properly design and maintain SCU systems,
particularly if implemented onsite. Turnover of land ownership,
where a new private entity with different business priorities inherits
an onsite SCU system, presents long-term operations and
maintenance (O&M) challenges. This can be further exacerbated by
a lack of understanding of SCU systems, unclear permitting
requirements, and potential delays in project approval, which are
additional hurdles that can inhibit SCU projects. NPDES stormwater
permits often include requirements for onsite post-construction
stormwater management as a "minimum measure." Public agency
and private landowners are both responsible for compliance and
therefore need effective mechanisms for coordination. Further
analyzing the challenges and opportunities that public stormwater
managers and private landowners face can help to develop
partnerships between these entities and further integrate SCU
solutions across individual parcels.

Alternative Project Delivery and Financing for SCU:

Stormwater infrastructure is traditionally implemented through a design-bid-build approach that may not be a good fit
when siting a large number of distributed, varied projects, such as green stormwater infrastructure and SCU practices.
When Prince George's County, Maryland, began developing its plan to retrofit 15,000 impervious acres using gray and
green stormwater infrastructure practices, the county worked with EPA Region 3 to develop a performance-based
alternative project delivery framework called the "Community-Based Public-Private Partnership" (CBP3). This approach
ntegrates project delivery services to reduce implementation costs and increase the pace of project delivery. A CBP3
program approach maximizes benefits to local workers and businesses by including performance-based targets for

Financial Incentives for Private Landowners in
New York City:

New York City's new programs provide financial
incentives through grants and rate discounts for
private landowners to implement green
infrastructure/SCU. Rate discounts of 25 percent
of water and up to 76 percent of wastewater
bills are offered to private industries that
implement and maintain onsite SCU systems.
The return on investment (ROI) for these
systems may be eight to 10 years, but the rate
discount is in perpetuity, which creates a
financial incentive for private developers.

Green roofs at Admiral's Row in Brooklyn, NY were
fundedin part, by grants provided through New
York City DEP's Green Infrastructure Grant Program.

Pure Potential: The Case for Stormwater Capture and Use

Strategic Framework for Capturing the Opportunity • 16


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community workforce and smail and minority-owned business utilization (EPA, 2021a). Retrofits on more than 2,000
impervious acres, including several SCU projects, have been implemented since the launch of the county's Clean Water
Partnership CBP3 program in 2014 (The Clean Water Partnership, 2022). Green infrastructure retrofit costs through this
approach are 30 percent less than traditional project delivery approaches. Attracted by the efficient delivery mechanism
the CBP3 provides, the state of Maryland supported the program with $48 million in Clean Water State Revolving Fund
(SRF) assistance—the largest Maryland SRF investment in stormwater. Using the CBP3 approach saved money, built locai
support, expanded available funding, and enabled rapid implementation of a large portfolio of green stormwater
Infrastructure projects in Prince George's County.

Using Rebates to Motivate Private Property Rainwater Harvesting:

The County of San Diego is facing requirements for dry weather flow elimination in 2021 and wet weather bacteria
reductions in 2031. As an approach to eliminating dry weather flows and reducing bacteria discharges from wet
weather, the county is using a human-centered design process to develop private property incentive programs as a cost-
effective compliance strategy and encourage residents and businesses to better manage, capture, and use stormwater
onsite. The Waterscape Rebate Program focuses on three types of projects: small residential and commercial parcels
that want to harvest rainwater, large landscapes that need help navigating the incentive process from multiple agency
programs, and partnerships with existing water efficiency programs from water supply agencies. Small-scale capture and
use projects and "large landscape projects" implemented and
approved within the first six months of the program are already
helping the county achieve compliance targets by reducing runoff
volume while simultaneously reducing water bills for residential and
commercial property owners.

The program has led to new investments in multiple-benefit
projects, such as a new partnership between the County of San
Diego and the San Diego County Water Authority that includes a $4
million investment from the county in existing landscape incentive
programs that produce water quality and supply benefits. A core
feature of the program is a simple benefit calculator that quantifies
performance for technical audiences like regulators and political
audiences. Stacking Incentives through partnerships heips water,
wastewater, and stormwater managers increase the funding pool,
leverage partner investments for better ROI, and cross-market to
source participants.

3. Expand Funding and Financing Mechanisms

Stormwater programs are constantly competing with wastewater and drinking water programs for federal and state grant
and loan opportunities. Thanks to recent initiatives—such as the BIL—funding opportunities for all water infrastructure,
including SCU projects, have never been greater. Nonetheless, stormwater managers need to persuasively communicate
the economic case for implementing SCU projects and develop innovative strategies for leveraging the robust federal.,
state, and private funding opportunities. The following actions are focused on evaluating SCU co-benefits to make the
business case for implementing these projects and helping stormwater managers unlock stormwater financing
opportunities.

Environmental Financial Advisory Board Report—Evaluating Stormwater Infrastructure Funding and Financing:

Section 4101 of the 2018 America's Water Infrastructure Act (AWIA) directed EPA to establish a stormwater
infrastructure funding task force "to conduct a study on, and develop recommendations to improve, the availability of
public and private sources of funding for the construction, rehabilitation, and operation and maintenance of stormwater
infrastructure" to meet the requirements of the Clean Water Act (CWA). The task force's recommendations were framed
under two overarching categories:

Rain barrels on private parcels in San Diego
County capture rainwater and hold it for later use
such as on lawns, gardens or indoor plants.

Pure Potential: The Case for Stormwater Capture and Use

Strategic Framework for Capturing the Opportunity • 17


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Allocate new federal stormwater funding: There is a need for increased federal investment in stormwater
infrastructure, with no offsets to other programs. Federal grants, loans, and new stormwater programs are
needed to fund critical stormwater infrastructure in communities of all sizes across the country and support
local funding sources,

Provide stormwater funding education and technical assistance: Educating the public and elected officials on
the need for stormwater funding is critical to the successful implementation of and community support for
funding solutions. Many communities need technical assistance related to evaluating and securing funding and
financing mechanisms.

Recommended Action: Evaluate and Publicize Methods for Characterizing and Monetizing the Co-Benefits
Associated with SCU

Although some funding programs evaluate project proposals only in terms of their ability to deliver a single type of benefit
(e.g., water quality improvements or water supply augmentation), funders are increasingly considering a wider range of
project benefits. Evaluating and communicating the co-benefits of SCU projects with public stakeholders and
decisionmakers is critical to build support for funding; identify opportunities to share costs; build community support for
SCU projects; and promote equitable and transparent decision-making.

Co-benefits associated with SCU projects are often difficult to monetize; however, decision support tools are being
implemented throughout the United States to begin monetizing the multiple co-benefits of stormwater infrastructure
projects. For example, the recently released "Community-Enabled Lifecycle Analysis of Stormwater Infrastructure Costs"
(CLASIC) (WRF, 2021a) and "Integrated Decision Support Tool" (l-DST) (Colorado School of Mines, 2022) decision support
tools enable quantitative and qualitative analysis of project co-benefits. The newly released "Framework and Tool for
Quantifying the Triple Bottom Line Benefits of Green Stormwater Infrastructure" (GSI-TBL) enables monetized estimates of
project benefits to assist with the comparison of project costs and benefits at community and/or watershed scales (WRF,
2021b). These tools, used individually or collectively, can help to communicate the benefits that exist and can be realized
by implementing SCU. While more robust methods for assessing co-benefits of SCU projects are now available, few
stormwater managers are using these tools in project design and analysis. The developers of CLASIC, i-DST, and GSI-TBL
should partner with EPA's Office of Research and Development to develop and provide more directed outreach and
training on the availability and use of these new tools to broaden their use in benefits evaluation. Project developers who
use these tools to evaluate SCU projects should work with the tool developers to determine if the suite of SCU practices
and technologies that these tools evaluate adequately represents the range of likely practices. A new WRAP action could
further test the utility of these co-benefit evaluation tools to support SCU planning and create additional training.

Los Angeles County Evaluates Multiple Co-Benefits of Proposed
Stormwater Capture Projects:

The county's Safe, Clean Water Program uses a stakeholder-driven process
to devise scoring criteria for evaluating potential project benefits. The
scoring committee evaluates water quality, water supply, community
benefit, and fund-leveraging criteria for each project. The committee
evaluates water quality—the highest-weighted evaluating factor—by
applying a cost-effectiveness ratio and considering project performance
through modeling analysis of water quality and water supply augmentation
benefits of prospective projects. The scoring committee also evaluates
water supply cost-benefit, as well as estimates of water supply gained
based on the county's Watershed Management Modeling System.

Community benefits, such as flood reduction, increased recreational
benefits, and community support, are evaluated through a qualitative
approach. This approach has enabled the county to gain community
support for multi-benefit project funding, as funded projects usually
provide direct community benefits in addition to less-visible water quality
and supply benefits.

Franklin D. Roosevelt Park

Regional Stormwater Capture Project

The proposed Franklin D. Roosevelt Park
Regional Stormwater Capture Project
plans to divert dry- and wet-weather flows
from the Glen Avenue Drainage System
and to provide pretreatment of water for
infiltration to the groundwater basin.

Pure Potential: The Case for Stormwater Capture and Use

Strategic Framework for Capturing the Opportunity 18


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Recommended Action: Clarify How Existing Financing Mechanisms Can Be Used to Pay for SCU Projects
The broader funding challenges and constraints that stormwater program managers face throughout the United States also
constrain the ability of communities to pursue SCU (WEF Stormwater Institute, 2021). Stormwater managers are often
unfamiliar with the full range of traditional and non-traditional funding sources and strategies currently available for
financing SCU projects or how to access those opportunities. The following federal, state, and local financing mechanisms
provide existing opportunities for stormwater managers to fund SCU initiatives:

Clean Water and Drinking Water SRF Programs:

The Clean Water (CW) and Drinking Water (DW) SRF programs provide opportunities for funding stormwater management
and SCU projects (EPA, 2021b). However, challenges such as repayment expectations (since stormwater programs typically
lack a dedicated revenue stream), legacy tendencies towards funding traditional wastewater treatment and drinking water
supply projects, and lack of awareness/experience with the flexibilities available through the SRF programs have prevented
stormwater managers from more broadly accessing these funding sources. The SRF programs have significant flexibilities
that enable them to fund stormwater projects (e.g., principal forgiveness, reduced interest rates, and funding preference
for green infrastructure and small/underserved community projects). For example, the CWSRF can provide flexible
repayment structures that allow for lower repayments as a recycled water program matures, with higher repayments
occurring later as rates approach the cost of service. The BIL provides additional SRF funding that can be used for SCU
projects, as well as offering additional flexibility to states to provide more SRF funding through grants than they would with
traditional SRF funding.

Implementation of these flexibilities varies by state, which may complicate communicating SRF funding possibilities to
stormwater managers. As of 2020, less than 2 percent of CWSRF assistance has gone toward stormwater projects over the
duration of the program (EPA, 2021c). Further guidance and case examples showcasing innovative SRF repayment
approaches and highlighting the flexibilities in designing repayment structures will demonstrate that stormwater
management projects, including SCU, are eligible for SRF funding. EPA should provide more information to clarify how
these flexibilities apply to SCU.

Federal and State Grant Opportunities:

The multiple co-benefits associated with SCU projects make them attractive for a variety of grant funding opportunities,
including the Sewer Overflow and Stormwater Reuse Municipal Grants (OSG) program and other programs in FEMA, the
U.S. Department of Housing and Urban Development, and the U.S. Bureau of Reclamation. Additional funding for SCU
projects may become available if the OSG program funding increases authorized in the BIL are appropriated in the future.
Furthermore, public funding programs like California's Prop IE and 84 programs specifically encourage multi-benefit
projects, such as SCU. However, many stormwater managers are not fully aware of these funding opportunities, and access
to funding search tools that better connect project

proponents to the most promising potential funding	Los Angeles County's Safe, Clean Water Program:

sources would help communities assemble the funding	passage 0f Measure W in 2018 created a

needed for SCU projects. An improved funding search tool, comprehensive, regional plan to address how Los Angeles
such as the proposed funding search tool being	County captures water and how the county can reduce its

implemented under WRAP Action 6.1, will enable	reliance on imported water. Developed in collaboration

communities to search for appropriate funding sources	wjth public health, environmental groups, cities, business,

more efficiently.	labor, and community-based organizations, the Safe,

Dedicated Revenue Streams:

Clean Water Program will provide Los Angeles County
with local, dedicated funding to increase their local water
Dedicated revenue streams, such as stormwater taxes and supply, improve water quality, and protect public health,
fees, are vital tools for financing community stormwater The program will generate approximately $300 million per
management initiatives. There may also be opportunities year from a special parcel tax of 2.5 cents per square foot
to apply revenue from drinking water, solid waste	of impermeable surface area—paved/built areas where

management, and other local fees to SCU projects under rainfall cannot be absorbed into the ground and instead
the right context. NMSA's "Building Excellence in	runs off as stormwater—on private property in the Los

Stormwater Management" toolbox provides useful	Angeles County Flood Control District (about $83 per year

guidance and resources to assist communities in	for the median home). The program also provides credits

establishing dedicated revenue streams for stormwater	f°r property owners who have installed stormwater

management.	capture improvements.

Pure Potential: The Case for Stormwater Capture and Use

Strategic Framework for Capturing the Opportunity • 19


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Municipal Bonds and Governmental Accounting Standards Board (GASB) 62:

Municipal bonds have long been a financing mechanism that cities and utilities use to fund capital investments. This
financing mechanism is available for all scales of SCU investments. GASB 62 clarified public accounting rules to better
enable disaggregated natural infrastructure to access public debt financing to support stormwater and green infrastructure
investment (Kelly et al., 2021). However, communities and bond counsels typically have not supported using public money
on land that they do not control or own. More widespread use of the changes in accounting rules can help communities
further leverage debt financing to support SCU projects on private land or implemented through public-private
partnerships.

Organizations such as NMSA, WaterNow Alliance, and private communication groups are committed to clarifying and
enabling wider adoption of existing financing mechanisms and strategies that can be applied to SCU. For example,
WaterNow Alliance's "Tap into Resilience Toolkit" provides an interactive, customizable platform designed to help water
leaders navigate tax, accounting, legal, and financial questions in order to initiate, implement, and scale sustainable
solutions, including SCU, for their communities. Future actions to build off these initiatives may include development of
guidance or training and focused outreach to stormwater managers.

Recommended Action: Clarify and Share Innovative SCU Financing Solutions

Many stormwater managers are unaware of new and innovative approaches to funding and financing capital costs and
long-term O&M for SCU projects. Federal and/or state leadership to assist communities in understanding the various
financing opportunities that can be applied to SCU implementation will be critical for building local capacity. Innovative
financing mechanisms already being applied throughout the United States include "pay-for-performance" structures, debt
financing, special utility districts, private property incentive fees, and tax abatement and rate discounts.

Allianz Field—Redeveloping the Snelling-Midway Site in Saint Paul, Minnesota:

When the City of Saint Paul and Minnesota United FC—the Twin Cities' newest professional sports franchise-
announced plans for a soccer stadium on a 35-acre brownfield site, the Capitol Region Watershed District (CRWD) saw
an opportunity to demonstrate stormwater innovation for thousands of district- and metro-area residents. Prior to
stadium construction, all stormwater runoff from the site was untreated and flowed directly to the Mississippi River. The
site's highly urbanized location, contamination, and lack of permeable surfaces have contributed to sediment and
nutrient impairments in the river. Based on the site master plan, the City of Saint Paul, Minnesota United FC, and site
owners RK Midway proposed construction of innovative green infrastructure practices, including comprehensive
rainwater and stormwater capture and reuse systems, as well as tree trenches and rain gardens to help improve water
quality, reduce use of potable water supplies, and enhance the city's tree canopy to reduce urban air temperatures and
improve air quality.

To fund the green infrastructure and rainwater harvesting system, the city amended their legislative code to create
green infrastructure stormwater management districts and authorized the collection of charges for payment of the
capital and annual maintenance and operational costs. As the foundation for the capital costs for construction, the team
and the city funded an amount of this combined system equivalent to the cost of the basic rate control and water quality
requirements of the CRWD. In addition, the Metropolitan Council, the State Clean Water Fund, and the Capitol Region
Watershed District provided grant funds. The city's share was paid out of revenue bond proceeds and will be paid back
via the Green Stormwater Infrastructure ordinance. This ordinance enables the city to charge a connection fee to new
developments that will rely on this new regional system, which is used to pay back the revenue bonds. For O&M, the city
is able to use its existing stormwater utility fee, as well as a green infrastructure annual surcharge that generates
revenue, to offset the cost of ongoing O&M.

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Resilient NYC Partners Private Incentive Program:

New York City Department of Environmental Protection's (DEP) Resilient NYC Partners program expands private property
incentives to build green infrastructure. The program was implemented through a $53 million third-party administrator
contract with an engineering firm in May 2021. The third-party administrator framework helps scale private property
retrofits by enabling expedient customer acquisition and green infrastructure practice siting through variety of project
delivery options. The administrator can work with a property owner's existing design and construction team or manage
the process entirely for property owners. The contract has a pre-determined stormwater volume-based incentive
payment structure based on DEP's analysis of historic public and private green infrastructure retrofit costs and the
availability of highly impervious sites across the city. The program goal is 250 greened acres In five years. The contract
also includes $2 million in performance payments that scale up as more greened acres are delivered.

Effectively communicating the benefits of voluntary stormwater retrofits to private property owners will be key to the
success of the program. DEP and its administrator have developed communication materials to demonstrate the
benefits of participation in the program clearly and effectively.

Benefits of Voluntary Stormwater Retrofits for Private Property Owners

(§1)

(—O-—J

vrv



Environmental

Social



• Demonstrate commitment to
sustainability and community

¦ Create customer interest and
increase public safety



•	Improve water quality and
health of local waterways

•	Enhance stormwater
management on site

•	Increase biodiversity with
green projects

A

•	Partner with the City in
stormwater and resiliency
initiatives

•	Reduce ponding on paved
surfaces used by customers
and staff



Investments that work for you and the community!

Stormwater utilities, fees, and taxes can be sustainable approaches to funding stormwater infrastructure projects, including
SCU; however, many municipalities currently lack the capacity and political support to establish and garner the public
and/or voter approval to create these funding structures. National guidance or training materials outlining different types
of fee structures (e.g., stormwater fees/level of service fees) and strategies for establishing stormwater utilities and flood
control districts will further help communities explore these opportunities for funding stormwater infrastructure projects.

Using Property Assessed Clean Energy (PACE) to Rapidly Scale Water Reuse Across Texas:

The National Wildlife Federation's Texas Coast and Water Program and Texas Water Trade's Rapidly Scaling Water Reuse
Across Texas: Using Property Assessed Clean Energy (PACE) Financing report examine the potential of PACE financing to
offset the upfront costs of onsite water reuse projects (where the storage, treatment and piping are all self-contained
onsite) and the costs incurred by private landowners to connect to the centralized reclaimed water system (for example,
dual plumbing a building to use water from the city's reclaimed water pipeline), in collaboration with the Texas PACE
Authority and Austin Water, the report models the savings of various water reuse approaches for typical commercial and
multi-family residential buildings to determine whether water reuse projects could meet stringent PACE financial tests.
Its findings indicate that PACE is an effective tool for enabling water reuse projects, although the economics of these
projects may require either utility rebates or co-financing with energy efficiency measures to meet the financial tests
applied to PACE-financed projects. While this report is specific to Texas, it is relevant anywhere PACE has been
authorized to fund water conservation efforts.

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Recommended Action: Assist Small and Underserved Communities in Accessing Funding Opportunities
Due to a lack of resources and available staff time to plan and
implement innovative water management practices, small and
underserved communities throughout the United States may be
disproportionately impacted by stormwater funding barriers.

Recognizing the unique stormwater management challenges that small
and underserved communities face—and developing resources to
make it easier for these communities to access stormwater funding
opportunities—will be critical to building local capacity for SCU in these
areas. For example, the funding search tool under development
pursuant to WRAP Action 6.1 would make it easier for communities to
find specific funding opportunities for which they are eligible.

Furthermore, as EPA and its partner agencies expand provision of
technical and planning assistance to help connect small and
underserved communities with available infrastructure funding through initiatives such as Justice40, it will be important to
offer assistance for stormwater and SCU infrastructure planning and financing, including possible establishment of
stormwater fees.

EPA's Integrated Planning Policy:

The Water Infrastructure Improvement Act added a new Section 402(s) to the CWA to include the 2012 Integrated
Municipal Stormwater and Wastewater Planning Approach Framework. EPA describes an integrated plan as a process
that identifies efficiencies from separate wastewater and stormwater programs to best prioritize capital investments and
achieve its human health and water quality objectives.

Recommended Action: EPA may consider broadening its integrated planning policy to embrace the full range of
interrelated water enterprises and activities beyond permitting and compliance for wastewater and stormwater
discharge regulation. Broadening the policy would encourage communities to consider the intersections between
wastewater, stormwater, drinking water, flood control, and water reuse planning and help communities obtain planning
resources, such as grants or loans, that can be applied in an integrated manner and at regional scales. Incentivizing
regional planning and framing stormwater management within an integrated water management strategy would further
enable stormwater managers to access a variety of federal and state funding sources.

4. Improve Regulations, Policy, and Guidance

Interest in SCU projects is often driven by regulatory drivers, such as the need to reduce water quality problems caused by
stormwater discharges. Federal, state, and local regulations can help build capacity for SCU by creating incentives to use
SCU as a compliance strategy and providing regulatory certainty to drive innovation. Federal leadership will be critical in
establishing regulatory frameworks for SCU that can be customized at state and local scales. The following priority actions
aim to address regulatory barriers to SCU consideration and take advantage of flexibilities to incentivize SCU
implementation.

Recommended Action: Develop a Compendium of NPDES Permitting Approaches for SCU Applications
Municipal stormwater permits vary substantially across states. In most states, NPDES permits focus on implementation of
minimum measures that, for the most part, do not address SCU potential. In addition, little guidance on how to address
SCU in NPDES permits is available to states with program authorization. For municipal separate storm sewer system (MS4)
permits that do address SCU, states may have difficulties in structuring permit provisions to credit implementation of SCU
projects to meet water quality-based requirements.

WRAP Action 8.5:

WRAP Action 8.5 is engaging underserved
communities in rural areas to evaluate needs
and opportunities to improve water security,
sustainability, and resilience through water
reuse, including SCU. Through this action,
EPA is providing training and pilot technical
assistance to address water recycling
opportunities and implementation obstacles.

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Permitting authorities have substantial flexibility in establishing effluent limitations, compliance paths, and other provisions
in NPDES permits. A white paper being developed under WRAP Action 2.6 discusses several of the permitting issues that
may affect the ability to pursue wastewater recycling and SCU. It contains
examples of how existing permit authorities have addressed these
challenges in permits. Post-construction standards and water quality-based
provisions in many MS4 permits have been structured to reduce polluted
stormwater discharges by requiring or encouraging implementation of
retention and detention practices that enable capture and use of
stormwater. Discovering innovative solutions to refine NPDES permitting
approaches and take advantage of permitting flexibilities (for stormwater
and other water sources that integrated solutions may encompass) can
help incentivize SCU planning and implementation within existing
regulatory frameworks. Compiling and disseminating case studies on how
states approach SCU within MS4 and wastewater discharge permits can
help identify commonalities and best practices for leveraging SCU solutions.

EPA's MS4 permit compendium series provides many examples of how
NPDES permitting approaches and conditions can be applied.

EPA's Office of Wastewater Management should lead the development of
this NPDES permitting compendium in coordination with the Association of
Clean Water Administrators, National Association of Clean Water Agencies,
and NMSA.

Recommended Action: Clarify How States Regulate Stormwater Capture and Use

SCU practitioners may be uncertain about which, if any, state reuse regulations apply to their projects. Few states have
water reuse regulatory structures that directly address SCU. Some states, including California and Florida, are beginning to
develop water reuse regulatory structures tailored for SCU; however, SCU projects have historically either been
unregulated or subject to reuse regulatory requirements developed for other types of water use.

Permitting Approaches for Dry Weather Diversions:

Controlled diversions from storm drains into wastewater collection systems can increase flows in the wastewater
management system that would be available for water reuse. The Orange County Sanitation District (OC San) and Los
Angeles County Sanitation Districts developed policies and guidelines for accepting dry weather flows in sanitary sewers,
requiring the stormwater management agency to obtain a diversion permit from the utility operating the sanitary sewer
(County Sanitation Districts of Los Angeles County, 2014; OC San, 2019). The OC San diversion permit requires OC San to
ensure its compliance with the source control provisions of its own NPDES permit.

The three water boards with NPDES permitting authority in coastal Southern California have not found it necessary to
include more specific permit provisions in wastewater or stormwater permits that control how storm drain diversions to
wastewater collection systems operate. The water boards concluded such provisions are unnecessary to ensure that
discharge requirements are met.

Although local authorities are successfully implementing many dry-weather diversion projects, some concerns remain
among stormwater and wastewater managers about how to permit diversion projects, define surveillance and
monitoring expectations, share risk and liability, and distribute/share costs that warrant further evaluation and research.

Incentivizing SCU in Industrial
Stormwater Permits:

California's industrial stormwater general
NPDES permit provides an alternative
compliance path, enabling industrial
facilities to partner with municipal
stormwater managers to implement
regional-scale projects incorporating SCU
instead of relying solely on onsite
stormwater controls (California State
Water Resources Control Board, 2018).
The state is now considering revisions to
the permit to address industry concerns
that certain requirements (e.g.,
limitations based on secondary maximum
contaminant levels for metals)
disincentivized SCU.

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Regulatory Drivers Leading to SCU innovation in San Mateo
County, California:

In 2015, the San Francisco Regional Water Quality Control Board
issued the countywide Municipal Regional Stormwater Permit
(MRP) to regulate stormwater discharges in San Mateo County.

The MRP requires all permittees to implement green
infrastructure improvements to reduce the amount of mercury
and polychlorinated biphenyl (PCB) in stormwater discharges to
the San Francisco Bay. The Orange Memorial Park Stormwater
Capture Project was designed to provide water quality
improvements and help meet the mercury and PCB requirements
of the San Francisco Bay MRP. This regional stormwater capture
project, the first of its kind in Northern California, diverts all dry-
weather flow and the first flush of urban stormwater runoff from
nearby Colma Creek into an underground system integrated within
the park. Once water is diverted into the park, the system treats the water to remove trash, debris, and sediment. A
large cistern under the sports field stores water for further treatment and disinfection so it can be used to meet
irrigation and other non-potable demands, saving over 15 million gallons of potable water per year. When full, the
cistern overflows into an infiltration gallery, which recharges 55 million gallons of groundwater every year.

The development of a compendium highlighting existing state regulatory frameworks pertaining to SCU would help clarify
the range of regulatory approaches being applied to SCU. A comparison of SCU regulatory practices would assist in the
potential development of national guidance and efforts by other states interested in developing SCU regulatory
frameworks. Case studies highlighting regulations, policies, guidance, and permitting approaches that have helped advance
the adoption of SCU may inspire other states and communities to adopt similar regulatory approaches. This action can be
used to compliment the work currently being completed by EPA, the WateReuse Association, the Association of Clean
Water Administrators, and the Association of State Drinking Water Administrators under WRAP Action 3.1 to compile
pertinent information about existing state-level regulations currently in place for water reuse.

State and local stakeholders are also increasingly interested in ensuring that adequate in-stream flows are maintained to
enable protection of ecosystem services when wastewater recycling and SCU projects are implemented. Obtaining the
necessary approvals from state fish and wildlife departments in situations where downstream flows may be impacted by
SCU implementation, particularly in water-scarce states, can be another challenge for stormwater practitioners looking to
adopt SCU projects. EPA should consider developing a WRAP action addressing the relationships between water recycling
activities and protection of in-stream environmental services through maintenance of minimum flows/ecological flows. This
action could address both the issues associated with identifying appropriate environmental flow requirements and the
capacity to use recycled wastewater and captured stormwater to augment in-stream flows (e.g., during dry periods of
lower natural flow).

Google's Global Water Strategy:

In September 2021, Google announced that by 2030, it will replenish 120 percent of the water it consumes by
continuing to address and advance the company's Operational water sustainability efforts and investing in community
water replenishment projects that improve the health of local watersheds where office campuses and data centers are
located. Complementing its replenishment and watershed health goal Google is committed to implementing water
efficiency measures, adopting water reuse practices that enable the company to recycle potable water, treating water
safely to meet water quality standards for non-potable reuse, and using alternative water suppliers from external
sources.

Google has recognized through its work with local government and community organizations that water is (In part) a
data problem. In response, Goggle is building tools to make data and technology more universally accessible, like
providing technology solutions for global surface water insights and flood forecasting (e.g., the Global Surface Water
Explorer).

A schematic displaying how captures stormwater is
stored and diverted for reuse throughout the
Orange Memorial Park Stormwater Capture Project.

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Private land managers face unclear and, at times, conflicting requirements concerning stormwater management that can
make it difficult to implement SCU on single parcels or to network SCU project planning across multiple ownerships.
WaterNow Alliance and the University of California, Irvine (UCI) School of Law Center for Land, Environment, and Natural
Resources (CLEANR) recently published a report— Tap into Resilience: Pathways for Localized Water Infrastructure—
outlining recommendations and actions for how these regulatory issues can be addressed with respect to parcel-scale SCU
and other decentralized strategies (Kelly et al., 2021). Further action is needed to help public and private land and
stormwater managers navigate regulatory frameworks and collaborate more efficiently in carrying out SCU projects across
ownerships and at larger geographic scales. Some companies and communities have recently initiated efforts to carry out
more integrated water management approaches involving both public and private ownerships to achieve greater impact at
watershed scales. EPA, NMSA, and interested companies should consider partnering to evaluate in greater detail the
challenges public and private landowners face in building broader-scale SCU implementation partnerships and strategies
for surmounting these barriers, drawing upon specific examples and initiatives where stormwater harvesting has succeeded
at broader scales.

Recommended Action: Evaluate State Water Rights Constraints
to SCU

State water rights law and implementation practices vary widely across
states. Water rights regulations and determinations in many western states
inhibit the ability to capture and use stormwater or rainwater based on a
concern that capture and use impinges on downstream water rights
dependent on that runoff (Luthy et al., 2019). Whether and how state
water rights provisions enable or restrict stormwater managers' ability to
pursue SCU is often unclear.

Innovative solutions may be needed to address SCU permitting constraints
imposed by longstanding state water rights. EPA should consider partnering
with states and water reuse proponents to systematically evaluate state
water rights constraints to SCU (and wastewater recycling) at different
scales and in different states to help build understanding of these
challenges and strategies to address them.

New York City Proposed Unified Stormwater Rule:

New York City's Unified Stormwater Rule includes amendments to align stormwater requirements across the city,
provide greater onsite stormwater management for new and redevelopment projects, and institute a retention-first
approach. The amendments expand the city's Stormwater Permitting Program, setting new thresholds for
compliance and a new retention-first approach for design of post-construction stormwater management practices. The
rule also includes a New York City Stormwater Manual to provide guidance for permit applicants.

5. Advance Science and Treatment Standards

Clarifying whether and how captured stormwater needs to be treated before use is critical to enabling broader SCU
implementation. Many jurisdictions are applying the risk-based framework and pathogen log reduction targets developed
by the NBRC for ONWS to determine stormwater treatment needs. However, there are concerns that applying treatment
standards developed to date based on this framework may be excessively stringent for SCU applications. Other
stakeholders are concerned that existing pollutant reduction targets may be insufficiently attentive to the pollutants
present in some stormwater. Important research is now underway to tailor development of risk-based treatment standards
for SCU to consider stormwater characteristics and the ability of different SCU practices to provide necessary levels of
treatment for the intended uses. This research will enable the development of guidance needed to inform treatment
standards for SCU projects. These treatment standards should be tailored to local and regional settings to account for
stormwater variability. Further research on the physical science of SCU and assessment of urban stormwater quality is
needed to develop methodologies for determining fit-for-purpose treatment standards.

Example State Water Rights Laws
Applicable to SCU:

Colorado recently allowed the capture of
rainwater from rooftop gutters for non-
potable outdoor uses, only with rain
barrels with a maximum combined
capacity of 110 gallons (Luthy et al.,

2019).

In Washington, a water right is needed to
capture and divert any stormwater runoff
for a consumptive use. Although there is
a de minimus allowance for home-scale
rain barrels, larger scale projects still
need a water right.

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Recommended Action: Develop Guidance on Determining
Treatment Standards for SCU Systems

Risk-based methods that can be used to develop treatment standards for
stormwater harvesting are similar to methods used to develop standards
applicable to wastewater recycling and other water quality-based
standards. The conventional approach has been to select end-point target
levels, which specify the acceptable threshold for a particular pollutant
surrogate (e.g., fecal indicator bacteria). However, these surrogates poorly
represent specific pathogens of concern and, therefore, associated
infection risks. An alternative approach, described in the NBRC for ON'vVS
risk-based framework, is to determine fit-for-purpose pathogen reduction
targets based on source water characteristics and desired end uses. This
approach helps evaluate how people are being exposed to pathogens in
water and identify the pathogen reductions (e.g., log reduction targets)
needed to protect human health at an acceptable risk level.

Adapting Risk-Based Frameworks for SCU
Treatment Standards:

California is developing new regulations
for stormwater, along with onsite
rainwater, greywater, and blackwater
recycling. With the help of an expert
panel, the state is adapting the NBRC for
ONWS' Risk-Based Framework for the
Development of Public Health Guidance
for Decentralized Non-Potable Water
Systems to set log-reduction targets for
each source water using available
stormwater quality data.

Washington, D.C., Stormwater Standards and Innovation:

In 2013, Washington, D.C., adopted retention and
detention-based standards and requirements for
stormwater. To meet these standards, the district
promotes a variety of green infrastructure practices,
including SCU. In 2020, Washington, D.C., adopted the
NBRC for ONWS log reduction targets as a simpier way for
engineers to design and treat for specific SCU end uses.
The Department of Energy & Environment continues to
work with utility partners and the public health
department to provide guidance to civil engineers on SCU
standards, which has enabled more SCU innovation
throughout the district. One such example of innovation
can be found in the district's historic canal system, Canai
Park, which implements a stormwater collection and
reuse system to collect and treat stormwater that falls
onsite. Collected stormwater meets up to 95 percent of
the park's needs for irrigation, its ice rink, and its
fountain, saving an estimated 1.5 million gallons per year.

Canal Park in Washington, D.C., incorporates cisterns, rain
gardens, and bioretention tree pits to capture, treat, and reuse
stormwater.

WRF Project 5034: Assessing the Microbial Risks and Potential Impacts from Stormwater Collection and Uses to Establish
Appropriate Best Management Practices:

This project will synthesize existing research on stormwater microbial quality and treatment processes to develop a
Stormwater Use Roadmap providing pragmatic guidance for design and operation of stormwater use systems. The
guidance will address selection of appropriate log reduction targets based on quality of stormwater and intended end
use, methodologies for monitoring stormwater microbial quality, and approaches for continuous monitoring of
operational systems to ensure safe water is reliably delivered (WRF, 2021c).

Guidance is needed to assist researchers and practitioners in adapting the NBRC for ONWS risk-based framework to
account for local and regional stormwater variability and selecting the correct tier within ranges of potential log reduction
targets. Such guidance should differentiate between centralized aquifer recharge systems and storage and direct-use
systems. The guidance should also focus on stormwater quality data and occurrence/fate of pollutants in urban stormwater

runoff. In addition, through WRAP Action 3.1, EPA has released the "Regulations and End-Use Specifications Explorer"
(REUSExplorer) that will compile existing state regulations for different water reuse applications—including onsite reuse.

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EPA will work to compile and analyze this information and consider the development of best practices that could provide
valuable information for SCU implementation.

Recommended Action: Bolster Research Pertaining to the Physical Science of SCU and Assessment of
Urban Stormwater Quality

The following research needs are critical for the development of fit-for-purpose treatment standards for SCU applications.

Augmentation of existing research efforts in determining human- and animal-sourced pathogen prevalence in
stormwater is needed to help SCU practitioners more accurately determine actual risks to exposure depending on
the catchment area and specific end use.

Additional monitoring and analysis are warranted to evaluate how well the log reduction target approach that is
applied to pathogens results in effective treatment for other problematic stormwater pollutants (e.g., metals,
nutrients, and salts) and to better understand per- and polyfluoroalkyl substances (PFAS) and other constituents
of emerging concern, such as hydrophilic organic compounds, in urban stormwater runoff.

Evaluation of the quality of stormwater based on seasonality and different land uses—considering regional
hydrologicaI variability—is needed to account for local and regional settings in the development of treatment
standards.

Successful communication and collaboration between researchers, regulators, and practitioners will be critical to
developing and implementing locally tailored treatment standards for SCU that are both protective of public and ecosystem
health and achievabie by available and affordable stormwater management technologies. Special consideration and
guidance may be warranted for applications of urban runoff for groundwater recharge, as urban stormwater for
groundwater recharge poses the risk of groundwater contamination and requires robust data, careful design, and
appropriate O&M to mitigate those risks (Luthy et a I2019). An EPA "state of the science" report was published in 2021
summarizing the current scientific literature on aquifer recharge using stormwater (EPA, 2021d).

Developing SCU Treatment Standards in Minnesota:

At the direction of the Minnesota Legislature, several Minnesota state agencies, have engaged with wastewater and
stormwater managers, researchers, and other stakeholders to evaluate regulatory and non-regulatory approaches to
advancing water reuse and inform development of state policies and regulatory mechanisms. As part of this effort, the
state agencies and stakeholders are evaluating SCU and associated potential health risks, treatment needs, and
regulatory structures. A principal area of focus in these discussions is the collection of stormwater in retention ponds for
use in landscape irrigation, which reduces groundwater withdrawals. As over-pumping of groundwater for landscape
irrigation is a significant concern in the State, the Legislature enacted a law in 2017 that exempts certain SCU projects
from having to obtain a state water appropriation permit.

A recent white paper studied the variability in stormwater quality and potential health risks from exposure to captured
stormwater used for different purposes, including landscape irrigation. A risk-based framework developed by the NBRC
for ONWS was evaluated by the Minnesota Department of Health
(MDI-I) to assist evaluation of SCU-related health risks and
treatment needs, taking into account a quantitative microbial risk
assessment developed using Minnesota stormwater data. During
engagement with stormwater managers and other stakeholders,
concerns have been raised about the need to balance protection
of public health from potential exposures to stormwater with the
need to enable cost-effective SCU project implementation and
avoid establishing excessively costly treatment requirements.

Discussions are continuing based on this work to evaluate
treatment needed for different uses, which could substantially
affect the costs of regulatory compliance, and whether SCU
practices should be regulated at the state or local level. In its white
paper, MDH recommended establishing a broader workgroup to
assist further research and development of a science-based
regulatory framework for SCU in Minnesota (MDH, 2022).

A stormwater collection pond in a Minnesota
neighborhood captures and temporarily stores
stormwater runoff.

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6. Accelerate the Use of New Technologies and SCU Strategies

Emerging technologies present opportunities to address stormwater quantity and quality challenges, meet fit-for-purpose
standards for the particular use, and employ a uniquely skilled workforce that can be locally sourced within a community.
The following actions are focused on testing and validating measurement, control, and treatment technologies for SCU
applications, as well as assisting stormwater managers with selecting the right technologies for SCU systems.

Recommended Action: Support Expansion of SCU Technology Validation Processes to Ease Regulatory
Acceptance

Developing a clear validation process for ensuring the effectiveness of control and treatment technologies will instill
confidence that the available SCU technologies can achieve water quality fit for specific end uses. Implementing validation
processes will depend upon the availability of robust data on technology performance in different settings and for different
pollutants. It will be important to evaluate whether sufficient performance data are available representing a wide enough
range of applications to enable robust practice evaluation and validation. Validation programs can help address data needs
by carefully specifying data requirements to support evaluation of new and existing technologies.

Initiatives, such as the national Stormwater Testing and Evaluation for Products and Practices (STEPP) program and the
American Society of Testing and Materials (ASTM) Committee E64 on Stormwater Control Measures, already exist to
promote knowledge on stormwater control measure (SCM) testing, validation, and treatment standards. Furthermore,
WRF's Tech Link online platform provides a forum for accelerating the uptake and deployment of innovative technologies.
Providing further support for these types of technology testing, validation, and adoption programs to expand and
incorporate SCU technologies can be helpful in establishing validation processes that ease regulatory acceptance.

STEPP Program:

The STEPP program is an NMSA initiative housed in the NMSA National Center of Excellence for Stormwater Testing and
Evaluation for Products and Practices. The STEPP program seeks to improve water quality via accelerating the adoption
of innovative stormwater management technologies by removing current barriers to innovation, creating regulatory
confidence, minimizing duplicative performance evaluation efforts, and establishing a nationwide framework for testing
and evaluating both public domain and proprietary stormwater control measures.

ASTM Committee E64 on Stormwater Control Measures:

The scope of the committee is to stimulate research and develop test methods, specifications, practices, guides, and
nomenclature for SCMs, including stormwater quality treatment; volume control; flow management; and runoff
detention, retention, and capture and use. The committee supports the STEPP program and provides a platform for
assessing SCM connections with existing standards and the development of new standards beyond STEPP.

WRF Tech Link:

The TechLink online platform promotes interaction in the water sector that enables municipal and industrial water,
wastewater, and stormwater agencies, as well as technology providers, consultants, academics, investors, federal
agencies, non-governmental organizations, and others, to advance the uptake of innovation. There is an opportunity to
incorporate more information on stormwater technologies into TechLink at this time.

Recommended Action: Update Existing National Stormwater Practice Databases to Support Validation of
SCU System Performance

A nationally accessible database to store effectiveness data and validation results for new and existing SCU technologies
would provide planners, developers, and stormwater managers with information necessary for selecting the right SCU
technology/configuration for their situation and use. Such a database should focus on urban runoff and a suite of chemicals
typically found in urban runoff that are mobile and persistent, including emerging contaminants such as PFAS and
hydrophilic organic compounds. Expanding the capability of existing databases (e.g., the International Stormwater Best
Management Practices [BMP] Database) to host these data would likely be more useful than creating a new database.

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Recommended Action: Validate and Propagate Robust Sensing and Control Devices to Measure Water
Quantity and Quality in SCU Systems

While significant progress has been made in using advanced stormwater sensing and control technologies, these
technologies are not uniformly understood or accepted as best practices. Further validation of sensing and control devices
that are internet-enabled to measure real-time water quantity and quality in SCU systems is needed to instill confidence in
the performance of existing and future stormwater control and treatment technologies. Real-time, dynamic monitoring
systems, such as Supervisory Control and Data Acquisition (SCADA) and other intelligent monitoring systems, are promising
ways of collecting robust stormwater data. However, information and case examples of how these kinds of measurement
systems are being implemented In SCU applications are not widely distributed.

Recommended Action: Identify Common SCU Technology Permutations to Enable Development of
Standardized Design Plans and Review Processes

Standardized approaches to designing, approving, and implementing SCU projects can help reduce upfront planning costs
for developers and make the review and approval process more manageable for stormwater managers and municipalities.
Due to the wide variety of SCU approaches and stormwater treatment technologies available, the process of selecting,
reviewing, and approving SCU design plans can be overwhelming for developers, stormwater managers, and municipal
officials, which can inhibit the adoption of SCU approaches. Identifying common SCU technology permutations for
developing more standardized plans can help streamline the design and approval phases of project development and make
it easier for communities to adopt SCU solutions.

Orange County Water District Groundwater Replenishment System:

A selenium TMDL was promulgated for San Diego Creek, a major inland creek and flood control facility. The watershed
sits over a historic terminal swamp area, where over millennia, selenium concentrated within the underlying soil.
Groundwater seeping into the creek and storm drainpipes contain selenium at concentrations above water quality limits.
However, given the lack of treatment options to remove selenium, dry-weather flow diversion to the sanitary system
again provided a regulatory solution, as well as a water recycling opportunity. With this project, flows are diverted to OC
San, which, in partnership with the Orange County Water District, operates the Groundwater Replenishment System
(GWRS). The GWRS uses advanced treatment processes consisting of microfiltration, reverse osmosis, and ultraviolet
light with hydrogen peroxide to purify treated wastewater and then use it to recharge the groundwater basin and
supplement drinking water supplies.

The Orange County Water District GWRS uses a three-step advanced treatment process to
produce high-quality water for replenishing the groundwater basin.

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CONCLUSION: KEYS TO UNLOCKING SCU POTENTIAL

Over the past two years, a diverse group of stormwater practitioners intensively explored SCU interests, experiences, and
development needs across the nation. These efforts revealed widespread interest in SCU, motivated by drivers and
challenges that vary substantially. Many communities have achieved remarkable successes in implementing multi-benefit
SCU projects and making SCU a central element in integrated local and regional water management. Although significant
challenges to more widespread SCU implementation remain, practitioners identified and are working to improve strategies
for surmounting financial, regulatory, scientific, technical, and social challenges that can make SCU implementation
difficult. This report highlights some of the most important opportunities and needs for action to build the nation's SCU
community of practice and make SCU a fully accepted tool in community water management planning. By implementing
these actions, the nation's capability to unlock the full potential of SCU and accelerate its implementation can be realized.

Stanford University has recently constructed a large-scale SCU project on the west side of campus that comprises stormwater
interceptors, swirl-type separators, sand filters, and a reverse pumping system that replenishes a nearby reservoir, Felt Lake.
Captured stormwater allows for irrigation of sports fields while preventing hydromodification and increased runoff into San
Francisquito Creek.

Pure Potential: The Case for Stormwater Capture and Use

Conclusion: Keys to Unlocking SCU Potential 30




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APPENDIX A: RECOMMENDED ACTIONS FOR ADDRESSING
SCU NEEDS

NOTE: Lead organizations are named for the recommended actions in the following tables where information is available.
Building Trust, Understanding, and Partnerships

Recommended Action and Lead Organization(s)

Develop a resource document designed to assist stormwater managers that are unfamiliar with the basic concepts of SCU
in pursuing these types of projects.

Leverage other actions in the WRAP to allow further dissemination of SCU resources and ideas. EPA should lead this
action with support from WRAP action leaders.

Develop a communications "toolkit" that compiles best practices and tools for outreach and engagement associated with
SCU project development and implementation. WateReuse is a potential partner for this action.

Compile and disseminate case studies of successful public-private partnership models for SCU implementation.

Analyze challenges that local public stormwater managers and private landowners face in integrating SCU activities onsite
and across individual parcels.

Conduct a formalized study to develop more consistent SCU messaging and terminology at the national scale. This can be
similar to the WateReuse study focused on vocabulary and images that support informed decisions about water recycling
and desalination.

Create knowledge-sharing networks to facilitate SCU conversations with an eye toward under-resourced utilities and
under-resourced stormwater management agencies. WRF, WateReuse, and EPA are potential leaders for this action.

Develop a suitability matrix depicting the range of SCU implementation strategies (including centralized vs. decentralized
and aquifer recharge vs. capture and direct use) based on local typology and water availability dynamics.

Develop more detailed estimates of SCU potential and implementation.

Funding Mechanisms

Recommended Action and Lead Organization(s)

Support efforts to expand SCU investments through infrastructure funding and financing for both traditional and non-
traditional approaches. This goal can be accomplished through training, education, engagement, and outreach to a
variety of stakeholders. These efforts will leverage ongoing work by the partner organizations on information
dissemination projects focusing on Government Accounting Standards Board (GASB 62) changes that better enable
distributed natural infrastructure, as well as overall information on the potential for debt financing to support
stormwater and green infrastructure investments. NMSA, WaterNow Alliance, and SGA Marketing are potential leaders
for this action pending availability of resources.

Assess opportunities to revise or create new models under the SRF programs to be more tailored to stormwater
programs (e.g., fewer restrictions on matching funds, grants and loans available for stormwater districts, or extra credits
for SCU implementation).

Compile and disseminate case studies of innovative financing approaches for SCU system capital costs and long-term
O&M.

Create grants to incentivize regional planning across water industries (e.g., stormwater, drinking water, and wastewater).
Grant application procedures should be simple and intuitive.

Develop a funding checklist for developers working on different stages of SCU projects.

Develop guidance on effective strategies for successful stormwater utility/fee programs that can support SCU, building on
existing tools in NMSA's National MS4 Online Resource.

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Regulations, Policy, and Guidance

Recommended Action and Lead Organization(s)

Develop a compendium of NPDES permitting approaches for SCU applications. EPA's Office of Wastewater Management
is a potential leader for this action.

Compile and disseminate regionally specific SCU updates, tools, and resources to assist communities within the same
region (i.e., regions with similar landscapes and/or climates) with addressing water management challenges.

Compile and assess linkages in existing state regulatory frameworks, policies and guidance, and local ordinances that
accelerate adoption of SCU planning and implementation.

Compile and disseminate onsite SCU operating permits that incorporate the NBRC for ONWS' risk-based framework.

Refine regulatory permit requirement frameworks to better enable SCU approaches, including direct use, injection,
spreading basins, etc.

Develop a clearinghouse of stormwater BMP manuals and guidance on stormwater treatment systems that can be
applied to SCU for direct use and aquifer storage projects.

Develop an internal EPA leadership caucus focused on SCU and the outcomes from this convening. EPA will lead this
recommended action.

If new NPDES permits are required for stormwater discharges from commercial and industrial facilities, potentially
incorporate language in the permit that incentivizes SCU at commercial, industrial, and institutional facilities as a
compliance strategy. EPA, the state of California, and other designated states are potential leaders for this action.

Support efforts to develop template documents (e.g., codes, ordinances, planning and design, and specifications) that
can more easily facilitate the local implementation of SCU practices, technologies, and approaches. NMSA is a potential
leader for this action, with support from other partners.

Develop permitting training that illustrates the use of available regulatory flexibilities to address SCU compliance issues as
an outgrowth of WRAP Action 2.6.

Science and Treatment Standards

Recommended Action and Lead Organization(s)

Develop design and treatment standards for drywells in California. The California State Water Resources Control Board
should lead this action.

Develop guidance on fit-for-purpose treatment standards for SCU. Separate guidance should be provided for aquifer
recharge vs. storage and direct use.

Prepare standard design plans for SCU systems that are certified (by a professional engineer) to meet specific treatment
standards to help developers save on up-front "soft costs" and allow for streamlined review. Non-prescribed alternatives
may be implemented if approved by a professional engineer as providing an equivalent level of treatment or better.

Pure Potential: The Case for Stormwater Capture and Use

Appendix A: Recommended Actions for Addressing SCU 32


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Technology Performance

Recommended Action and Lead Organization(s)

Expand the STEPP initiative to include SCU practices, technologies, and approaches to support the confidence in the
performance. NMSA should lead this recommended action.

Where possible, include SCU practices, technologies, and approaches in efforts to develop standards through Committee
E64 (Stormwater Control Measures) of the ASTM to support the STEPP initiative. NMSA should lead this recommended
action.

Adapt existing International Stormwater BMP database to track and assist validation of the performance of existing SCU
systems. This should focus on urban runoff and a suite of chemicals typically found in urban runoff that may be
problematic depending on the end use. WRF, WateReuse, and grantees are potential leaders for this action.

Validate and propagate robust sensing and control devices that are internet-enabled to measure both water quantity and
quality in SCU systems.

Develop a framework for SCU workforce development for underserved communities. New York City DEP is a potential
leader for this action with possible support from the Johnson Foundation.

Pure Potential: The Case for Stormwater Capture and Use

Appendix A: Recommended Actions for Addressing SCU 33


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APPENDIX B: KEY SCU RESEARCH NEEDS

Building Trust, Understanding, and Partnerships

The following priorities were identified as key research needs for addressing organizational challenges and developing

successful communication strategies.

¦	Evaluate models/frameworks for interagency, interjurisdictional, and public-private cooperation.

¦	Develop collaboration frameworks to facilitate cooperation across water enterprises (stormwater, drinking water,
wastewater).

¦	Derive inter-organizational lessons learned from case studies and wastewater coordination studies (can build off
the work being done under WRAP Action 2.16).

¦	Research "words that work" to communicate about specific SCU co-benefits to different audiences.

¦	Evaluate local efforts to build support for SCU and derive lessons learned to help others effectively build capacity.

Funding Mechanisms

The following priorities were identified as key research needs for addressing financial challenges for implementing urban

SCU projects.

¦	Evaluate methods available to characterize co-benefits, especially difficult-to-quantify benefits like flood control,
flow augmentation, and community economic benefits.

¦	Compile data and examples on SCU funding and financing approaches, including innovative approaches.

¦	Research opportunities and impediments to accessing SRF, OSG, and other funding sources (EPA's Section 319
Nonpoint Source Management Program, Community Development Block Grant, FEMA, Bureau of Reclamation,
Department of Transportation, etc.)

¦	Identify potential innovative funding and public-private partnership (P3) approaches to funding SCU projects.

¦	Develop cost comparisons for SCU systems vs. wastewater recycling systems.

¦	Evaluate the feasibility and potential for trading and banking mechanisms for SCU.

Regulations, Policy, and Guidance

The following priorities were identified as key research needs for addressing regulatory challenges for implementing urban

SCU projects.

¦	Evaluate state water rights constraints to SCU at different scales in different states.

¦	Evaluate and compare current approaches for setting stormwater treatment standards for fit-for-purpose
applications.

¦	Evaluate NPDES and Underground Injection Control regulatory effects on the ability to pursue SCU (WRAP Actions
2.6 and 7.4).

¦	Evaluate legal frameworks for stormwater diversion to sanitary sewers that can supplement water recycling
opportunities and publicize examples of local regulation of diversion projects.

¦	Evaluate strategies for creating regulatory incentives for SCU through MS4s and other legal mechanisms, such as
alternative compliance paths in MS4 permits.

¦	Evaluate the effects of local codes on and enable networking across ownerships to develop SCU projects
addressing stormwater from multiple parcels.

¦	Evaluate regulatory instruments for maintaining SCU assets.

¦	Evaluate the relationships between water recycling activities, including SCU, and ecosystem services, such as
maintenance of minimum in-stream flows.

¦	Evaluate lessons learned from the wetlands mitigation banking community for potential application to SCU.

Pure Potential: The Case for Stormwater Capture and Use	Appendix B: Key SCU Research Needs • 34


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Science and Treatment Standards

The following priorities were identified as key research needs pertaining to the physical science of urban SCU and
assessment of urban stormwater quality.

¦	Evaluate needs to identify treatment and performance standards for emerging contaminants in stormwater.

¦	Evaluate the quality of stormwater from different land uses considering regional hydrological variability.

¦	Evaluate risks to groundwater quality posed by different forms of stormwater used for infiltration and aquifer
recharge.

¦	Evaluate the effects of large-scale and distributed SCU systems on stream/environmental flows.

¦	Develop risk-based frameworks and guidance for urban SCU, focusing on stormwater quality data and
occurrence/fate of pollutants in stormwater.

¦	Evaluate methods for determining the effectiveness of distributed SCU systems in yielding claimed benefits at
watershed scales.

¦	Collect better data on human pathogen prevalence in stormwater in different urban settings, along with chemical
source trackers. Correlate the chemical source trackers to infrastructure condition, sanitary sewer materials and
condition, and homeless populations.

¦	Develop pathogen indicators to evaluate human influences faster and more easily than quantitative microbial risk
assessment (QMRA).

¦	Evaluate in-situ monitoring methods to flag the presence of pathogens in stormwater.

¦	Develop standard operating procedures for design of SCU systems (one for aquifer recharge and one for direct
use).

¦	Consider a set of criteria (e.g., infrastructure condition, presence and location of wastewater collection systems,
exposure for treated water, intended use) to qualify systems into a "minimum treatment requirement" bin.

¦	Evaluate the impacts of infrastructure condition and location (wastewater and stormwater) on stormwater
quality (e.g., pathogens and human source trackers).

Technology Performance

The following priorities were identified as key research needs pertaining to the validation of control and treatment
technologies incorporated in urban SCU systems.

¦	Evaluate the efficacy of existing stormwater treatment technologies and BMPs in removing bacteria, metals,
organics, and sediment.

¦	Evaluate capacity of real-time monitoring and sensor technology to enable dynamic system operation to manage
infrastructure and risks of pollutant introduction.

¦	Evaluate the potential for technology validation processes to ease regulatory acceptance.

¦	Evaluate long term O&M issues with SCU technologies and capacity to maintain designed treatment efficacy.

¦	Evaluate surface and subsurface storage options and capacity to retrofit existing infrastructure to enable storage.

¦	Evaluate cost and cost-effectiveness to assess cut points in terms of treatment feasibility.

¦	Identify common SCU technology combinations and permutations for developing standardized design plans and
review processes.

Pure Potential: The Case for Stormwater Capture and Use

Appendix B: Key SCU Research Needs • 35




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APPENDIX C: NOTES AND REFERENCES

Aguilar, M., & Brown, S. (2020). Potential volume of stormwater capture for consumptive use in the United States.
Memorandum from Marcus Aguillar and Seth Brown to David Smith. https://nationalstormwateralliance.org/wp-
content/uploads/2022/02/Natl-SW-Capture-and-Reuse.pdf

California State Water Resources Control Board. (2018). General permit for storm water discharges associated with
industrial activities—NPDES No. CAS000001, adopted 2014 and amended in 2015 and 2018.
https://www.waterboards.ca.gov/water issues/programs/stormwater/igp 20140057dwq.html

Clean Water Partnership. (2022). The Clean Water Partnership, https://thecleanwaterpartnership.com

Colorado School of Mines. (2022). Integrated decision support tool. Colorado School of Mines, https://idst.mines.edu

Cooley, H., & Phurisamban, R. (2016). The cost of alternative water supply and efficiency options in California. Pacific
Institute. https://pacinst.org/wp-content/uploads/2016/10/PI TheCostofAlternativeWaterSupplvEfficiencvOptionsinCA.pdf

Cooley, H., Thebo, A., Abraham, S., Shimabuku, M., & Gleick, P. (2022). The Untapped Potential of California's Water Supply:
Urban Efficiency, Water Reuse, and Stormwater Capture. Oakland, CA. Report in preparation.

County Sanitation Districts of Los Angeles. (2014). Dry Weather Urban Runoff Diversion Policy.
https://www.lacsd.org/home/showpublisheddocument/2126/63764285019340000Q

Dieter, C.A., Maupin, M.A., Caldwell, R.R., Harris, M.A., Ivahnenka, T.I., Lovelace, J.K., Barber, N.L., & Linsey, K.S. (2018).
Estimated use of water in the United States in 2015: U.S. Geological Survey Circular 1441, 65 p.
https://doi.org/10.3133/cirl441. [Supersedes USGS Open-File Report 2017-1131.]

Dirringer, S., Shimabuku, M., & Cooley, H. (2021). Economic evaluation of stormwater capture and its multiple benefits in
California. PLoS ONE, 15(3), e0230549. https://doi.org/10.1371/iournal.pone.0230549

Fassman-Beck, E., Schiff, K., & Apt., D. (2020). Evaluating potential methods to quantify stormwater capture: SCCWRP
technical report 1116. Southern California Coastal Water Research Project.

https://ftp.sccwrp.org/pub/download/DOCUMENTS/TechnicalReports/1116 StormwaterCapture.pdf

Garrison, N., Sahl, J., Duggar, A., & Wilkinson, R. (2014). Stormwater capture potential in urban and suburban California-
issue brief. Pacific Institute, https://pacinst.org/publication/stormwater-capture-potential-in-urban-and-suburban-
california-issue-brief

Gleick, P., & Cooley, H. (2021). Freshwater scarcity. Annual Review of Environment and Resources, 46, 319-348.
https://www.annualreviews.org/doi/full/10.1146/annurev-environ-012220-101319

Kelly, M.L., Koch, C., Koehler, C., & Camacho, A.E. (2021). Tap into resilience: pathways for localized water infrastructure.
WaterNow Alliance and University of California, Irvine (UCI) School of Law Center for Land, Environment, and Natural
Resources, https://www.law.uci.edu/centers/cleanr/news-pdfs/tap-into-resilience-report.pdf

Luthy, R.G., Sharvelle, S., & Dillon, P. (2019). Urban stormwater to enhance water supply. Environmental Science &
Technology, 53(10), 5534-5542. https://pubs.acs.org/doi/10.1021/acs.est.8b05913

Minnesota Department of Health. (2022). Reuse of stormwater and rainwater in Minnesota—a public health perspective.
https://www.health.state.mn.us/communities/environment/water/docs/cwf/wpwaterreuse.pdf

National Blue Ribbon Commission for Onsite Non-Potable Water Systems, U.S. Water Alliance, & Water Research
Foundation. (2018). Making the utility case for onsite non-potable water systems, https://watereuse.org/wp-
content/uploads/2019/10/NBRC Utility-Case-for-ONWS 032818.pdf.pdf

Orange County Environmental Protection Division. (2019). 2019 FSA awards program submittal form— Lake Lawne

stormwater reuse facility. Florida Stormwater Association. https://www.florida-

storm water.org/assets/MemberServices/AwardsProgram/2019/OA%20-%200range%20County.pdf





Pure Potential: The Case for Stormwater Capture and Use

Appendix C: Notes and References 36














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Orange County Sanitation District. (2019). Ordinance No. OCSD-53.
https://www.ocsan.gov/home/showpublisheddocument/28457/63701465310543000Q

Rauch-Williams, T., Marshall, M.R., & Davis, D.J. (2018). Baseline data to establish the current amount of resource recovery
from WRRFs. Water Environment Federation. https://www.wef.orR/Rlobalassets/assets-wef/direct-download-
library/public/03—resources/WSEC-2018-TR-003

Southern California Water Coalition (SCWC). (2018). Stormwater capture: enhancing recharge & direct use through data
collection. SCWC Stormwater Task Force. https://socalwater.orR/wp-content/uploads/scwc-2018-stormwater-
whitepaper 75220.pdf

U.S. Environmental Protection Agency. (2004). Report to Congress on Impacts and Control of Combined Sewer Overflows
and Sanitary Sewer Overflows. EPA 833-R-04-001. https://www.epa.Rov/sites/default/files/2015-
10/documents/csossortc2004 full.pdf

U.S. Environmental Protection Agency. (2016). Clean Watersheds Needs Survey 2012 Report to Congress. EPA-830-R-15005.
https://www.epa.Rov/sites/default/files/2015-12/documents/cwns 2012 report to conRress-508-opt.pdf

U.S. Environmental Protection Agency. (2021a). Financing green infrastructure—is a community-based public-private
partnerships (CBP3) right for you? https://www.epa.Rov/G3/financinR-Rreen-infrastructure-community-based-public-
private-partnerships-cbp3-riRht-you

U.S. Environmental Protection Agency. (2021b). Integrating water reuse into the clean water state revolving fund.
https://www.epa.Rov/sites/default/files/2021-04/documents/cwsrf water reuse best practices.pdf

U.S. Environmental Protection Agency. (2021c). Clean water SRF program information: national summary.
https://www.epa.Rov/sites/default/files/2021-02/documents/us20.pdf

U.S. Environmental Protection Agency. (2021d). Enhanced Aquifer Recharge of Stormwater in the United States: State of the
Science Review. https://cfpub.epa.Rov/si/si public record Report.cfm?dirEntrvld=352238&Lab=CPHEA

WaterNow Alliance. (2021). The tap into resilience toolkit. Tap into Resilience. https://tapin.waternow.orR/toolkit

Water Environment Federation Stormwater Institute. (2021). 2020 National Municipal Separate Storm Sewer System (MS4)
Needs Assessment Survey Results. https://wefstormwaterinstitute.orR/wp-
content/uploads/2021/02/WEF MS4 Needs Assessment Survey Full Report 2020 Final.pdf

Water Environment & Reuse Foundation. (2017). Risk-Based Framework for the Development of Public Health Guidance for
Decentralized Non-Potable Water Systems. https://watereuse.orR/wp-content/uploads/2019/ll/Risk-Based-Framework-
for-DNWS-Report FINAL.pdf

Water Research Foundation. (2021a). Community-enabled lifecycle analysis of stormwater infrastructure costs (CLASIC).
https://www.waterrf.orR/CLASIC

Water Research Foundation. (2021b). Economic framework and tools for quantifying and monetizing the triple bottom line
benefits of green stormwater infrastructure (WRF project number 4852).

https://www.waterrf.orR/research/proiects/economic-framework-and-tools-quantifvinR-and-monetizinR-triple-bottom-line

Water Research Foundation. (2021c). Assessing the microbial risks and potential impacts from stormwater collection and
uses to establish appropriate best management practices (WRF project number 5034).

https://www.waterrf.orR/research/proiects/assessinR-microbial-risks-and-potential-impacts-stormwater-collection-and-
uses

Pure Potential: The Case for Stormwater Capture and Use

Appendix C: Notes and References • 37




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Photo Credits

Cover: Los Angeles County Department of Public Works, WateReuse Association, Water Innovation Services, The Johnson
Foundation at Wingspread, Washington D.C. Department of Energy and Environment; Pg. 6: Water Innovation Services,
WateReuse Association, National Municipal Stormwater Alliance, Re-Inventing the Nation's Urban Water Infrastructure,
Water Environment Federation, The Johnson Foundation, U.S. EPA; Pg. 9: Orange County, FL; Pg. 14: New York City
Department of Environmental Protection; Pg. 16: New York City Department of Environmental Protection; Pg. 17: Water
Innovation Services; Pg. 18: Los Angeles County Department of Public Works; Pg. 21: New York City Department of
Environmental Protection; Pg. 24: San Mateo County, CA, Pg. 26: Washington D.C. Department of Energy and Environment;
Pg. 27: Water Innovation Services; Pg. 29: WateReuse Association; Pg. 30: Re-Inventing the Nation's Urban Water
Infrastructure

Pure Potential: The Case for Stormwater Capture and Use

Appendix C: Notes and References • 38


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APPENDIX D: ACRONYMS

¦	ASTM -American Society of Testing and Materials

¦	AWIA-America's Water Infrastructure Act

¦	BIL- Bipartisan Infrastructure Law

¦	BMP - Best Management Practices

¦	CBP3 - Community-Based Public-Private Partnerships

¦	CLASIC - Community-Enabled Lifecycle Analysis of Stormwater Infrastructure Costs

¦	CRWD-Capitol Region Watershed District

¦	CSO - Combined Sewer Overflow

¦	CWA-Clean Water Act

¦	CWSRF - Clean Water State Revolving Fund

¦	DWSRF - Drinking Water State Revolving Fund

¦	EPA - U.S. Environmental Protection Agency

¦	FEMA - Federal Emergency Management Agency

¦	GASB - Governmental Accounting Standards Board

¦	GSI-TBL- Framework and Tool for Quantifying the Triple Bottom Line Benefits of Green Stormwater
Infrastructure

¦	GWRS - Groundwater Replenishment System

¦	l-DST-Integrated Decision Support Tool

¦	MDH - Minnesota Department of Health

¦	MRP - Municipal Regional Stormwater Permit

¦	MS4 - Municipal Separate Storm Sewer System

¦	NBRC for ONWS - National Blue Ribbon Commission for Onsite Non-Potable Water Systems

¦	NEWR- Non-Potable Environmental and Economic Water Reuse Decision Support Tool

¦	NMSA- National Municipal Stormwater Alliance

¦	NPDES - National Pollutant Discharge Elimination System

¦	NYC DEP - New York City Department of Environmental Protection

¦	OC San - Orange County Sanitation District

¦	O&M - Operations and Maintenance

¦	OSG - Sewer Overflow and Stormwater Reuse Municipal Grants

¦	P3 - Public-Private Partnership

¦	PACE - Property Assessed Clean Energy

¦	PCB - Polychlorinated Biphenyl

¦	PFAS - Per- and PolyfluoroaIkyl Substances

¦	QMRA- Quantitative Microbial Risk Assessment

¦	ReNUWIt- Re-Inventing the Nation's Urban Water Infrastructure

¦	REUSExplorer - Regulations and End-Use Specifications Explorer

¦	SCADA - Supervisory Control and Data Acquisition

¦	SCM - Stormwater Control Measure

¦	SCU - Stormwater Capture and Use

Pure Potential: The Case for Stormwater Capture and Use	Appendix D: Acronyms • 39


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SCWC - Southern California Water Coalition

STEPP - Stormwater Testing and Evaluation for Products and Practices Program
TMDL-Total Maximum Daily Load

UCI CLEANR- University of California, Irvine, School of Law Center for Land, Environment, and Natural Resources

WateReuse - WateReuse Association

WEF - Water Environment Federation

WRAP - Water Reuse Action Plan

WRF-Water Research Foundation

MERIDIAN

Environmental

www.erg.com

INSTITUTE

Report prepared by Meridian Institute, PG Environmental, and Eastern Research Group, Inc.

Pure Potential: The Case for Stormwater Capture and Use

Appendix D: Acronyms • 40


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