Braga, Andrea

Andrea is a principal water resources engineer with over 18 years of experience. She leads Jacobs Water Team in New England. Andrea specializes in HH modeling and manages the full gamut of civil and water infrastructure projects from critical repairs to sanitary force mains, to wastewater treatment plant facilities planning, to flood mitigation planning and resiliency.

Titles from this speaker

Description: Bar Harbor Systemwide Conveyance Assessment: How Smart Controls Helped the Town...

Bar Harbor Systemwide Conveyance Assessment: How Smart Controls Helped the Town Develop a Cost-Effective Solution to Meet CSO Mitigation Requirements

Abstract

Introduction: The Town of Bar Harbor, ME (the Town), a popular tourist destination due to its proximity to Acadia National Park, operates four CSOs that discharge to Frenchman's Bay where water recreation is highly valued. The Town has two wastewater treatment facilities (WWTF); included in NPDES permits for the WWTFs are requirements for development, and periodic updates, of a CSO Master Plan to abate CSOs from the Town's four CSO outfalls. Bar Harbor prepared its first CSO Master Plan in 2006, the most recent update to the plan was approved by the Maine Department of the Environment (MEDEP) in 2021. The purpose of the CSO Master Plan is to identify abatement projects and intended implementation schedule to better control and reduce CSOs and to report on progress towards achieving those results. Project Overview: A systemwide conveyance assessment was conducted to evaluate the potential hydraulic performance for infrastructure improvements and infiltration/inflow (I&I) reduction projects identified in the CSO Master Plan and to develop a plan for other pump station, force main, storage and interceptor improvements needed to increase the system's hydraulic capacity, eliminate SSOs, and reduce CSOs to the levels of control identified in the plan. The CSO Master Plan's minimum level of control is a 1€year, 24€hour storm event producing 2.4 inches of rainfall as 'the benchmark by which alternatives are evaluated and cost€effective solutions identified.' Subsequent discussions with MEDEP in 2021 related to the West Street Pump Station (PS) CSO outfall (Outfall #007) and a feasibility study prepared in 2019, identified a 5€year, 24€hour rain event as the design storm for the solution(s). Out of the four remaining CSOs in the sewer collection system, the West Street PS CSO discharging to Eddie Brook is the highest priority for the Town's CSO reduction efforts based on potential impacts to public use and benefit of the receiving waters. A collection system hydraulic model was needed to characterize existing conditions, operations, and performance, and to evaluate cost-effective solutions to mitigate CSO's in the Town to the CSO Master Plan's level of control. The model was developed and calibrated with data from pump stations, the WWTFs, and flow meters installed in the collection system. A Jacobs 'autocalibration' tool enabled a cost-efficient and expedited calibration to the nine flow meters and other data points. Once calibrated, the model was used to evaluate proposed improvements to the collection system needed to eliminate SSOs and sewer backups, and reduce CSO overflows to the CSO Master Plan's level of control. The following goals were established for the analysis: 1.Eliminate CSOs at the West Street PS CSO outfall (Outfall #007) for the 5-year, 24-hour design storm. 2.Elimination of CSOs at the Rodick Street PS outfall (Outfall #006) and Main Pump Station (or Lower Main) outfall (Outfall #004) for the 1-year, 24-hour design storm. 3.Eliminate SSOs at known problem areas in the collection system for up to the 5-year, 24-hour design storm. Results/Benefits: A list of pump station, force main, storage and interceptor improvement projects were conceptualized to increase the collection system's hydraulic capacity and meet the stated assessment goals. The Town had several planned Capital Improvement Projects (CIP) that were included in the alternatives developed; however, prior to the model development, the Town had no way to quantify the potential improvement from these projects. The alternatives were combined in several different combinations to determine the most effective scenarios to achieve the assessment goals. The five most effective scenarios with respect to feasibility and performance were identified and modeled. Each scenario was evaluated with implementing three levels of I&I reduction (i.e., 0%, 25%, and 50%). Conceptual cost estimates for each scenario were developed to further assess the cost-effectiveness of each alternative and its performance towards achieving the assessment goals. This scenario evaluation identified that by optimizing the operation of the West Street PS and CSO Storage Tank project (a $9M project already in design), combined with an upgrade to the Town's Main Street Pump Station (with a combined cost of $4.7M), assessment goals were nearly achieved. The West Street PS project's original design goal was to provide storage for the 5-year, 24-hour event to mitigate CSOs from CSO Outfall #007; the tank was not originally utilized for lower volume storm events and thus the project not maximizing the benefits from the Town's infrastructure investment. By modeling the system using smart, real-time controls, the evaluation showed that the storage tank should be utilized for storage during smaller events, without compromising its goal eliminate CSOs from the West Street CSO Outfall during the 5-year event. The evaluation showed that with these two infrastructure improvement projects, combined with implementation of a 25% I&I reduction program, the Town would not need to complete other CIP projects originally thought to be necessary to meet assessment goals — saving the Town millions of dollars in unnecessary infrastructure improvements. Conclusion: The systemwide conveyance assessment of the collection system is complete and the Town has a plan to achieve CSO mitigation regulatory requirements, as stated in their CSO Master Plan. The West Street PS and CSO Storage Tank Project design is nearing completion and is planned to go out to bid in spring 2024 with construction starting in early summer 2024. With this assessment complete, the Town has the data and information necessary to justify to their ratepayers the benefits and necessity of the ongoing system improvements and planned capital investments into the collection system. The Town also has the data and information necessary to justify the effectiveness of the planned capital improvements to the MEDEP and the information to support completion of the next CSO Master Plan Update which is required to be submitted to ME DEP by March 28, 2027. With the collection system upgrades planned, once constructed, the Town will also have the real-time data needed to verify system improvements are meeting their CSO mitigation goals and the ability to adapt system logic, if necessary, to improve system performance. A truly adaptive solution.

This paper was presented at the WEF Collection Systems and Stormwater Conference, April 9-12, 2024.

SpeakerBraga, Andrea

Presentation time

13:30:00

14:00:00

Session time

13:30:00

16:45:00

SessionCombined Sewer Overflow

Session number07

Session locationConnecticut Convention Center, Hartford, Connecticut

TopicCollaboration, Combined Sewer Overflow, Combined Sewer System, Construction, Deep Sewer Tunnel, Flow control, Long Term Control Planning, Modeling, Predictive Analytics, Public Education/Information/Communication, Pump station, forcemain, Regulatory Compliance - Collection Systems, Sewer Separation, Wet Weather

Author(s)

Braga, Andrea

Author(s)A. Braga1, M. Dever1, B. Leavitt

Author affiliation(s)Jacobs 1

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Apr 2024

DOI10.2175/193864718825159383

Volume / Issue

Content sourceCollection Systems and Stormwater Conference

Word count21

Description: Perfecting Defect Coding and Recommendations Using AI: The Power of Optimized QC and...

Perfecting Defect Coding and Recommendations Using AI: The Power of Optimized QC and Historic Data

Abstract

Utilities across the country are dealing with aging wastewater collection infrastructure as well as increased sewer flows due to new developments. These pressures require careful system management. To assess collection system health and to find deteriorated pipes in need of rehabilitation or replacement, utilities perform condition assessments, typically conducted using pole cameras, acoustic equipment, or closed-circuit television (CCTV) inspections. CCTV being the most robust method as the entire length of the pipeline is able to be visually observed and assessed. Performing CCTV inspections and coding pipe condition defects is a time-consuming and often tedious task which requires defect coding training and refreshers. Even with training, managers need to assure inspectors are coding uniformly. It is common for two different defect coders to describe a defect differently and to apply different codes. Additionally, watching CCTV footage for hours is monotonous and requires long-term attentiveness as the coder scans the pipe for observations. This can be exhausting and lead to mistakes and staff turnover. To resolve these problems, the industry is moving towards automated coding of CCTV defects using artificial intelligence (AI). The benefit is that AI processes the camera feed and scans for defects without getting tired. The downfall is that while CCTV AI coding has progressed, AI coding is not yet perfect. Since utilities rely on defect coding's accuracy to prioritize maintenance, replacement, and management of their collection systems, AI CCTV coding companies have had to incorporate a layer of QC to ensure the condition assessment results of the AI output can be relied upon by the utilities. In our presentation, we will focus on the history of AI tools for the effective management of buried assets. We will look at two applications of AI: visual recognition AI, used for automated coding of CCTV defects on inspection videos, and predictive AI, used for determining pipe degradation based on existing defects. We will not only look at the benefits of AI but also look at the limitations. We will drill into the most difficult defect types for AI to recognize and the importance of quality control (QC). Through two case studies, we will compare AI coded pipeline condition assessments to inspector coded pipeline condition assessments. We will explore how AI and optimized QC was able to detect nuanced defects that were either missed, overlooked, or misclassified by the human inspectors. We will also look at the benefits of keeping and maintaining historic data records. Utilities should note that condition assessment is not a once-and-done process. Repeated condition assessments help track deterioration over time and help establish a reliable and resilient conveyance system. Condition assessment tracking also helps utilities adopt proactive maintenance cycles instead of just reactive maintenance. We will look at an additional case study where historic CCTV inspections were re-coded to enhance their asset management analysis, leading to significant cost savings. This presentation on leveraging AI for visual defect recognition and coding, importance of augmented QC and data driven asset management will assist utilities with streamlining operational procedures, allocation of resources and capital planning. These tools also help utilities to catalogue inspection data effectively essentially creating a comprehensive database that is easily accessible.

This paper was presented at the WEF Collection Systems and Stormwater Conference, April 9-12, 2024.

SpeakerBraga, Andrea

Presentation time

09:00:00

09:30:00

Session time

08:30:00

10:00:00

SessionAsset Optimization

Session number15

Session locationConnecticut Convention Center, Hartford, Connecticut

TopicArtificial Intelligence, Asset Management, Condition Assessment, Effective Utility Solutions, GIS, Hydrogen Sulfide, Odor and Corrosion Control, Rehabilitation

Author(s)

Graham, Ryan

Author(s)R. Graham1, C. Kennedy, P. Praturi1

Author affiliation(s)Jacobs 1

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Apr 2024

DOI10.2175/193864718825159374

Volume / Issue

Content sourceCollection Systems and Stormwater Conference

Word count16

Trenchless Repair of Critical Sanitary Force Main

Abstract

The Norwich Public Utilities (NPU) combined sewer system dates to the mid-19th century. Deferred maintenance, infiltration, grit, and aging infrastructure have contributed to much of the system becoming physically and functionally obsolete. This presentation provides a discussion about the repair of a segment of compromised 24-inch ductile iron force main located beneath the Yantic River in Norwich, CT and the collaborative effort between Norwich Public Utilities and Vortex Services to complete the repair. The force main conveys more than half of the City's wastewater to the Norwich wastewater treatment plant, including large volumes of combined sewer flows during wet weather. Based on observed sanitary discharge to the tidally influenced Yantic River in January 2020, NPU and Jacobs Engineering began the investigation of the apparent force main failure. It was determined that the 24-inch force main had developed a leak near the west bank of the east channel of the Yantic River. NPU took emergency action by installing a dewatering well adjacent to the broken pipe and pumping directly into the force main downstream of the break. This temporary measure mitigated discharge to the river and allowed the development of a plan to install over 700 feet of HDPE sewer bypass and isolate the damaged section of force main. After bypassing flows from the damaged section of force main, it was determined that the leak was below river surface elevation, evident by the significant amount of infiltration seen entering the force main. NPU hired Vortex Services to clean and inspect the pipeline using CCTV and sonar technologies. By tethering foam pigs, camera, and sonar, the approximate location of the leak was determined. Using data from the sonar and CCTV inspection in addition to available record information and field measurements, construction documents were drafted, and the work was put to public bid. The proposed work would consist of the installation of one or two internal pipe seal sleeves to slow or stop infiltration followed by installation of a glass pressure liner system through the 150-foot length. Despite reasonable contractor interest in the construction documents, response to the bid was limited and considerably higher than expected. The bid was not awarded because of the high cost for the proposed work. Most of the overpriced work was associated with excavation and dewatering, which was not surprising given the limited information available about subsurface conditions. Jacobs and NPU worked together to restructure the construction documents and allocate the portions of work that appeared to be overpriced to NPU underground crews. The construction documents were developed in a manner that would allow the NPU to complete excavation, dewatering, and disassembly of the force main to the fittings just below the river elevation at low tide. Installation of two sacrificial lengths of C900 PVC coupled to the existing ductile iron force main allowed the excavations to be backfilled to grade, so that most of the remaining repair and lining work could occur without excavation, at ground surface. This feature saved countless hours of excavation, re-excavation, and dewatering during the remaining phases of the work. Jacobs reconfigured the construction documents to reflect a scope of work associated with the repair of the leaking force main with internal pipe seal sleeves. There were several issues with the installation of the internal pipe seal sleeves, the most impactful being the extensive deterioration of the ductile iron pipe. Based on the CCTV and sonar data, it was assumed that the damaged section of force main was limited to a single point of failure just above the lower fitting. During the installation of the internal pipe seal sleeve, it was determined that the actual extent of the damage was more involved than initially thought. Working with the contractor, a series of internal pipe seal sleeves were installed in an overlapping/shingled pattern. While this slowed the infiltration, the volume of infiltration was still too high to allow for the installation of a CIPP liner as planned. A plan was then made to stop the gushing Infiltration using Cured-in-Place (CIP) segmental liners installed on top of the internal pipe seal sleeves. The CIP segmental liners were installed beyond the limits of damaged pipe to prevent infiltration from following behind the liners. After the infiltration was stopped, the contract documents were revised to show a scope of work limited to the installation of the Cured-in-Place Pipe (CIPP) liner and two end seals with a required test pressure of 75 psi. Excavation and dewatering for the installation of the end seals would be completed by NPU in collaboration with the lining contractor's schedule. The first attempted lining was aborted when defects in the liner material were noticed by the contractor just prior to installing the liner. The second attempt ended with a cured liner installed in place. Pressure testing of the liner revealed minor pressure losses. The pressure loss issues are being resolved at the time this abstract is submitted. The presentation will expand on the most interesting aspects of the work: -The cost savings associated with bifurcating the work to move the more uncertain work efforts associated with excavation and dewatering to the NPU underground crew. -The advantages associated with public utilities having capable and competent work crews. -The financial benefit associated with rehabilitation over replacement-based alternatives. -The value realized when there is collaboration between owner, contractor, and engineer.

This paper was presented at the WEF Collection Systems and Stormwater Conference, April 9-12, 2024.

SpeakerBraga, Andrea

Presentation time

09:00:00

09:30:00

Session time

08:30:00

10:00:00

SessionTrenchless Installation

Session number27

Session locationConnecticut Convention Center, Hartford, Connecticut

TopicBypass pumping, Combined Sewer Overflow, Combined Sewer System, Construction, Cured-In-Place Pipe Assessment, Design considerations, Rehabilitation, Trenchless Technology