Executive Summary
Infrastructure degradation is a chronic problem for fats, oils, and grease (FOG)
pretreatment programs at wastewater utilities, which can lead to harmful bypass and high loss of
a renewable energy feedstock. Additionally, infrastructure compliance rates are a challenge from
a management perspective, with an estimated 30% compliance rate nationwide (Environmental
Protection Agency, 2017). When a device begins to degrade, it often does not cause a sudden
problem; rather it is a chronic problem that builds up over time. Prematurely identifying
degrading infrastructure and possible FOG bypass has long-term benefits for the utility, the
sewer infrastructure, and the restaurant. Many attempts to address these problems focus on a topdown, engineering-focused approach that continuously has limited the interventions because they
do not incorporate concepts of equity, future-thinking, and social context (Kibert, 2007). This
project fills an important gap in the sustainable development literature by providing a concrete
example where hard and soft infrastructure can be combined to achieve community
sustainability, infrastructure compliance, institutional resilience, and business equity.
Throughout this project, there have been major gaps identified in the infrastructure
management of FOG pretreatment programs at the City of Tempe. Previously the TGC has
utilized the traditional enforcement model to address infrastructure issues, but this strategy
lacked a critical, holistic, systems thinking perspective, which contradicted the sustainabilityfocus of the business advocacy and regulatory partnership model that is foundational to the
TGC’s success. Through the desired future-state vision of the City of Tempe, it quickly became
clear that a sustainable approach to infrastructure management was necessary to achieve these
long-term goals. The method to achieve these strategic goals was to identify an intervention
point at the intersection of infrastructure compliance, restaurant equity and advocacy, and
resource recovery.
The gaps identified in the City of Tempe FOG Pretreatment Program were (1) inequity
between TGC members and non-TGC restaurants when replacing or repairing FOG
infrastructure (2) the existing workflow for identifying repairs in TGC members was
inconsistent, inefficient, and did not value the partnership approach (3) the repair and
replacement process for non-TGC members was not reflective of stakeholder needs, including
education and advocacy. Intervention points to address these gaps were identified through the

Applied Project Methodology of the National Resource Council (National Academy of Science,
1983). The significance of this approach to the project methodologies is that this framework
connects specific actions and pathways with their critical context and application. The process
places emphasis on human-technology systems to optimize performance beyond the current state
through observational analysis, surveys, system data, future scenario planning, and an on-going
evaluation of intervention success. It was important to utilize a methodology that applied easyto-follow steps and a narrative of the entire process, including critical decision-making context
so that these intervention points could be adapted to other wastewater utilities.
The findings of this research resulted in five intervention points and a series of
deliverables to help the program reach its future vision, which are interconnected in order to
provide a holistic approach. The intervention points are (1) Program Recommendations, which
provide two additional intervention points that align with the goals but were outside the scope of
the project (2) FOG Resource Packet, which provides a comprehensive, educational tool for
restaurants to better understand the replacement process (3) TGC Repairs and Compliance,
which is a new workflow to provide a more resilient compliance process utilizing a hard and soft
infrastructure approach (4) Vendor Registry, which provides an alternative pathway for
recruiting qualified vendors to perform high-quality, grease management services and (5) the
Grease Trap Assistance Program, which balances the inequities between TGC and non-TGC
members by providing financial assistance for infrastructure upgrades. The next step is to share
the infrastructure management solution with other municipalities to better support the FOG
pretreatment programs that affect our regional wastewater treatment.
By providing the tools for community businesses to maintain their infrastructure longterm, the issue of infrastructure degradation can be addressed with both a hard and soft
infrastructure approach which fulfills a gap in the current sustainable infrastructure literature.
Through a comprehensive approach to infrastructure assistance, including internal
administration, funding, and external partner messaging, this program can cultivate a community
where sewer health, environmental longevity, and resource recovery are local values and shift
the paradigm from enforcement to partnership.