Sacramento Area Sewer District
Sacramento, California
The Central Trunk Sewer is an eight mile pipeline that conveys both residential and industrial
sewage for Sacramento County. Constructed in the 1960’s of unlined reinforced concrete, the
pipeline ranges from 33-inches to 60-inches in diameter and is located deep under major roads,
residential backyards, creeks, protected wetlands, and a state highway. Nearly 50 years of
corrosion has severely deteriorated the pipeline and restoring the structural stability of the
pipeline in a cost effective manner with minimal decrease in capacity and distribution to the
community became the primary goals for the Sacramento Area Sewer District (SASD). To meet
these goals SASD and their design consultant West Yost Associates (West Yost) chose cured-inplace
pipe (CIPP) to rehabilitate the entire eight mile pipeline alignment.
Throughout construction several lessons have been learned from this large CIPP project. This
paper will discuss some of the lessons learned as well as considerations for owners and designers
regarding quality control and quality assurance of liner samples, bypass vs. plugging sewer
flows, environmental mitigation monitoring and reporting program, public outreach, air quality
regulations, construction noise mitigation, and debris estimating.
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Posted: May 20th, 2011 | Filed under: >1M, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: CIPP Rehabilitation, Corrosion Prevention, Environmental Impact, Improved Customer Relations, Improved Sewer Rehabilitation, Increased Sewer Life, Minimized Community Disruption, Noise Mitigation, Pipe Construction Alternative, Reduced Inflow and Infiltration | No Comments »
Orange County Sanitation District (OCSD)
Orange County, California
Wastewater from the coastal areas of the City of Huntington Beach are conveyed to the Orange
County Sanitation District’s Treatment Plant No. 2 through a 1350 mm/1800 mm/2100mm PVC
(Polyvinyl Chloride) lined RCP (Reinforced Concrete Pipe)sewer. The sewer was constructed in
the early 1980′s to service an area that included residential development at the north end that did
not occur due to overwhelming environmental issues. Since then, the sewer has conveyed
substantially lower flows and the portion of the sewer not lined with PVC has been exposed to
corrosive sewer gases and has corroded.
This project included a full evaluation of the condition of the sewer and looked at alternatives for
repair. Ultimately, the course of action included a unique solution that allowed the line to be
rehabilitated with a minimum of impact and disturbance to surface improvements including hotel
resorts and beach activities particularly during the summer.
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Posted: May 20th, 2011 | Filed under: >1M, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: CIPP Rehabilitation, Corrosion Prevention, Environmental Impact, Improved Customer Relations, Improved Sewer Rehabilitation, Increased Sewer Life, Minimized Community Disruption, Noise Mitigation, Pipe Construction Alternative, Reduced Inflow and Infiltration | No Comments »
Manholes represent a rather complex structure for assessing its structural condition and
“leakiness” potential. Factors such as the assembly of components with multiple construction
materials and exposure mechanisms to rainfall and runoff make computational scoring and I/I
quantification logic complicated. Manholes have the potential to be significant sources of
extraneous infiltration/inflow (I/I) but it is difficult converting visual inspections into I/I
quantification. The American Society of Civil Engineers (ASCE) 2009 publication titled
Manhole Inspection and Rehabilitation and other publications were used to develop an analysis
tool for assigning infiltration/inflow (I/I) to standard manhole defects and projecting the I/I rates
to vary with specific storm event rainfall frequency, intensity, and duration. The tool also adjusts
the I/I rates depending the defect’s component location and on which one of four rainfall runoff
exposure mechanisms the manhole is exposed; sheet-flow, ponding/tributary limited,
ponding/tributary un-limited, and elevated. The tool’s I/I quantification process and development
basis improves the engineering integrity of rehabilitation cost effective analysis and prioritization
decisions.
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Posted: May 20th, 2011 | Filed under: Sanitary Sewer, Stormwater | Tags: Improved Manhole Rehabilitation, Improved Organization, Improved Plant Efficiency, Manhole Prioritization, Reduced Infiltration and Inflow | No Comments »
Green Bay Metropolitan Sewerage District (GBMSD)
Green Bay, Wisconsin
The Green Bay Metropolitan Sewerage District (GBMSD) used the principles presented in
Effective Utility Management, a Primer for Water and Wastewater Utilities in development of its
Strategic Plan and Solids Management Plan. The self-assessment and attributes of a Highly
Effective Utility were crucial to the successful development and implementation of these plans.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Effective Utility Management, Environmental Impact, Improved Strategic Planning, Optimized Self-Assessment, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions, Solids Management Planning | No Comments »
Louisville and Jefferson County Metropolitan Sewer District (MSD)
Louisville, Kentucky
In response to a Consent Decree entered into Federal Court in August of 2005, the Louisville and
Jefferson County Metropolitan Sewer District (MSD) developed an Integrated Overflow
Abatement Plan (IOAP) to control the community’s combined sewer overflows (CSOs) and
sanitary sewer overflows (SSOs). The Consent Decree contained a provision for stakeholders to
participate in the development and implementation of the Long-Term Control Plan and the
Sanitary Sewer Discharge Plan.
Recognizing that the development of the IOAP Program would represent a major investment for
the community, MSD expanded the influence of the stakeholder group to assist in developing
community support for the investments necessary to comply with the Consent Decree
requirements.
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Posted: May 20th, 2011 | Filed under: 500K-1M, Sanitary Sewer, Stormwater, Water Treatment | Tags: Combined Sewer Overflow (CSO) Control, Cost Savings, Increased Community Support, Overflow Abatement Plant, Plant Optimization, Regulatory Compliance, Sanitary Sewer Overflow (SSO) Control | No Comments »
Fort Wayne City Utilities
Fort Wayne, Indiana
The City of Fort Wayne set out to develop a rain garden demonstration and incentive program to
ensure the success of their campaign. An aggressive marketing and public information effort
helped the community begin to recognize, support, and adopt the program as their own.
However, the rain garden program is just the first step in their “Green Infrastructure Initiative”.
They are hopeful this program will be a springboard to look at the overall sustainability
component of their wet weather control and conveyance infrastructure, and start a broader
marketing effort within the community for cleaner and safer water. The goal is that their rain
garden program will quickly become the basis for future green infrastructure, and be the leading
example for other sustainable programs.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Environmental Impact, Green Infrastructure, Improved Customer Relations, Improved Neighbor Relations, Plant Sustainability, Provide Cleaner Water, Rain Gardens, Reduced Carbon Footprint, Water Conservation, Wet Weather Control | No Comments »
Philadelphia Water Department (PWD)
Philadelphia, Pennsylvania
The Philadelphia Water Department (PWD) is currently evaluating the implementation of
various combined sewer overflow (CSO) control alternatives. This includes traditional
engineering approaches that rely on physical infrastructure (e.g., building large diameter
tunnels), as well as more “natural” approaches that rely on “green infrastructure” techniques
(e.g., vegetated bioswales, permeable pavement).This report provides a Triple Bottom Lineoriented
benefit-cost assessment of the CSO control alternatives under consideration by PWD.
The focus is on the benefits and external costs of the alternatives. The key finding of this report
is that the green infrastructure approaches generate a broader and more valuable array of
environmental, public health, and social benefits than do traditional CSO control strategies.
Benefits of green infrastructure evaluated and monetized include: Improved recreation
opportunities, increased property values, reduced heat-stress related fatalities, improved air and
water quality, green jobs, reduced energy use, and reduced disruption due to construction and
maintenance activities.
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Posted: May 20th, 2011 | Filed under: >1M, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Combined Sewer Overflow (CSO) Control, Environmental Impact, Green Infrastructure, Improved Customer Relations, Improved Public Health, Improved Stormwater Management, Low Impact Development, Permeable Pavement, Plant Sustainability, Rain Gardens, Vegetated Bioswales | No Comments »
Water & Sewer Authority of Cabarrus County (WSACC)
Concord, North Carolina
The Water & Sewer Authority of Cabarrus County (WSACC) teamed with CH2M HILL to
explore beneficial use of waste heat produced by their biosolids incinerator in the face of rising
energy costs and an increased emphasis on sustainability. Studies showed the resulting heat at full
utilization could generate up to 2MW – equivalent to powering 1400 homes.
The project team worked with specialty legal counsel to obtain a first-of-its-kind ruling that
classified WSACC biosolids as a ‘renewable fuel’, with the intent of selling the electricity rather
than using it at their plant. The ruling allowed this energy to be sold at a premium…nearly double
their retail rate. This revenue stream could produce $1M-$1.3M annually.
Project findings are relevant to facilities that incinerate biosolids as well as utilities considering
projects involving ‘green’ power generation. Rethinking traditional payback models and
capitalizing on emerging renewable energy markets could give utilities millions of reasons to “Go
Green”.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Green Infrastrucute, Heat Recovery, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Washington Suburban Sanitary Commission (WSSC)
Laurel, Maryland
The Washington Suburban Sanitary Commission (WSSC) serves 1.8 million residents with water
and wastewater service with 2 surface water treatment facilities and 5 wastewater treatment
plants. In an effort to reduce operating costs and encourage sustainable practices the
Commission entered into a series of agreements with an Energy Services Company (ESCO) to
perform Energy Performing Contracts (EPCs). These alternative delivery projects involved theCost
Commission conducting upgrades to water and wastewater treatment facilities based on
guarantees of reduced operating expenditures.
In this project delivery and financing method, the ESCO in conjunction with the Commission
and the owners engineer conducted preliminary evaluations of treatment processes in an effort to
identify opportunities for reduction in operating expenses (power consumption, demand
management, solids disposal and fuel usage, based on a 15 year payback period. Upon
agreement between the owner and the ESCO as to the process improvement, construction cost
and reduction in operating costs, the owner and ESCO entered in an agreement whereby the
ESCO designed and constructed the improvement (under a modified design-build process) and
the ESCO guaranteed the projected operations savings for a 15 year period.
The first series of project involved the expenditure of $10.2 M in construction and design cost
with a guaranteed annual savings of $700,000 per year. In the first two years of operation, these
projects have saved $1,500,000 per year. While these figures indicate that the Commission has
been able to have its cake and eat it too, “There ain’t no such thing as a free lunch”
(TANSTAFL)”. The process and implementation of these projects demonstrated a number of
lessons to the Commission in how to conduct the initial evaluation, design, construction and
verification of energy savings. This paper will detail the challenges and lessons learned from the
ESCO process and demonstrate the path to success for future ESCO projects.
The process demonstrated the importance of well defined and consistent design standard,
particularly for instrumentation and control, electrical and HVAC systems. The Commission
was challenged with developing and writing appropriate contractual terms at the preliminary
design stage, as that is stage at which the project cost is established and requirements for
equipment are developed. In addition, the Commission was challenged with balancing the
desires and requirements of multiple groups including operations, engineering, finance, and
power management. The paper will present examples of each of the challenges, along with solutions to the challenges that allow the Commission to continue with this project delivery
method with greater success.
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Posted: May 20th, 2011 | Filed under: >1M, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Optimization, Energy Savings, Evironmental Impact, Improved Plant Efficiency, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions, Reduced Operating Costs | No Comments »
Wastewater collection system odor and corrosion issues continue to grow in importance to
communities and to conveyance system owners and operators. Odor and corrosion prevention in
collection systems has been as much art as science. Common control methods are typically
selected based on field experience as opposed to a fundamental understanding of why and when
methods will be successful. Although much is known regarding the cause of odorous gases in the
collection system, the underlying science and mechanisms of odor generation, sewer ventilation,
odor characterization and monitoring, and corrosion mechanisms need further research. This
Water Environment Research Foundation (WERF) research project helps the industry transition
from “odor artists” to scientists and engineers, enabling designers to successfully prevent odor
and corrosion events through proper design and for operators to mitigate and prevent odor
excursions from existing systems.
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Posted: May 3rd, 2011 | Filed under: Sanitary Sewer, Stormwater, Waste Water Treatment | Tags: Corrosion Prevention, Improved Customer Relations, Odor Characterization and Monitoring, Odor Prevention, Sewer Ventilation | No Comments »