Heath, Gregory

Mr. Heath is a Vice President at AECOM and has been with the firm for 40 years. He serves as the firms North America Practice Leader for Wet Weather...

Joined:

About Heath, Gregory

Mr. Heath is a Vice President at AECOM and has been with the firm for 40 years. He serves as the firms North America Practice Leader for Wet Weather Treatment. Mr. Heath supports the pursuit and execution of wet weather projects throughout North America and on key international assignments. He is experienced in all phases of project delivery from planning through detailed design, construction, and commissioning. Mr. Heath is currently active on the WEF Collection Systems and Municipal Resource Recovery Design Committees.

Heath, Gregory

Titles from this speaker

Innovative Design-Build Implementation of CSO Storage in Lewiston, Maine

Abstract

The Lewiston Auburn Water Pollution Control Authority (LAWPCA) is required to construct a combined sewer overflow (CSO) storage tank to reduce the frequency and volume of CSO discharges into the Androscoggin River from Structure B and Outfall 002 located at the Wastewater Treatment Plant (WWTP). This project will be implemented using a conventional design build (DB) approach. The WWTP is designed to handle an average daily flow of 14.2 million gallons per day (MGD) but currently treats an average daily flow of about 8 MGD. During wet weather the collection systems from Auburn and Lewiston can deliver flows approaching 50 MGD to the WWTP. Excess wet weather flow, above the peak flow capable of being treated through the full WWTP treatment process, overflows from Structure B to the Androscoggin River via a 48-inch outfall leading to Outfall 002. Control of overflows from Structure B is the OBJECTIVE of this DB project. The WWTP currently has sufficient influent pumping capacity to pump and treat a peak flow of 32 MGD. LAWPCA is currently advancing plans to increase the firm WWTP peak flow pumping and treatment capacity to 38 MGD and the 2.1-million-gallon (MG) CSO Storage Facility capacity is based on a 38 MGD WWTP capacity. Purpose of Paper and Presentation: The purpose of this paper and presentation is to convey how LAWPCA structured their conventional DB RFP to provide proposers with considerable latitude to develop and offer LAWPCA a best value solution to their needs while requiring CSO storage site utilization that will preserve options for expanding CSO storage if required in the future. Project Scope: The services in this DB project include engineering, design, permitting, and procurement of materials and equipment, construction, testing, start-up, and commissioning of the LAWPCA CSO Storage Facility. Overflow from downstream of Structure B and upstream of the Outfall 002 discharge location will be intercepted at a Diversion Structure and conveyed to a CSO Storage Pump Station with a firm capacity of 30 MGD. The CSO Storage Pump Station will pump to the Storage Tank(s). Following each storm event, the Storage Tank(s) will be dewatered by gravity to the WWTP for full treatment. The Diversion Structure, CSO Storage Pump Station, and Storage Tank(s) are required to be located within limits shown on an indicative drawing included in the DB procurement document (see attached figure). Major facilities, components, and functions that make up the CSO Storage Facility include the Diversion Structure, CSO Storage Pump Station, Storage Tank(s), ancillary piping (e.g., Diversion Structure to CSO Pump Station, CSO Pump Station to Storage Tank, Storage Tank drain, process water, etc.), Support Building including a garage bay and an Electrical and Control Room, and replacement of an existing stand-by generator. Examples of how the project technical requirements for selected facilities, components, and functions that make up the CSO Storage Facility provide proposers with flexibility while preserving LAWPCA with operational and future flexibility are presented in Table 1. Status of Completion: The design-build RFP, which is the subject of this abstract submittal, was completed in August 2023. Selection of a design builder will be completed by early 2024 with design and construction of the LAWPCA CSO Storage Facility underway by the time this conference takes place in April 2024. Benefits of Presentation: The primary benefit to those attending this presentation will be the opportunity to learn how LAWPCA was innovative in developing their conventional DB RFP to both provide latitude to proposers while preserving their options for future CSO storage expansion. The paper and presentation will expand on the examples in Table 1, above. Additional benefits will include learning how DB can be used to implement time-sensitive wet weather projects and how excess wet weather flow storage can be cost-effectively integrated into an active wastewater treatment plant process and site. Conclusion: The LAWPCA CSO Storage Facility is an important project in attaining regulatory compliance in accordance with long-term CSO control plan requirements and for improving the water quality of the Androscoggin River. Project financing and affordability are important to LAWPCA and citizens of Auburn and Lewiston. ARPA funds, which must be expended by the end of calendar year 2026, will be used to reduce the local cost burden. Selection of conventional DB for implementation of this CSO Storage Facility project will enable LAWPCA to meet that date and take advantage of a best value solution while preserving options for potential future CSO storage needs.

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

SpeakerMignone, Kate

Presentation time

13:30:00

16:45:00

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)

Mignone, Kate

Author(s)K. Mignone1, G. Heath1, T. Peaslee2, O. McCullough3

Author affiliation(s)AECOM 1; Lewiston Auburn Water Poll Ctl, 2; Sebago Technics, Inc. 3

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Apr 2024

DOI10.2175/193864718825159357

Volume / Issue

Content sourceCollection Systems and Stormwater Conference

Word count10

Post-Construction Assessment of the North Dorchester Bay Tunnel System

Abstract

The Massachusetts Water Resources Authority (MWRA) is currently conducting a combined sewer overflow (CSO) Post Construction Monitoring and Performance Assessment, a multi-year study to measure the performance of its $912 million long-term CSO control plan (LTCP). One of MWRA's completed activities is the North Dorchester Bay (NDB) Tunnel performance assessment. The purpose of this presentation will be to provide a brief summary of the MWRA LTCP, the NDB Tunnel system, and the work performed to demonstrate that the NDB Tunnel system has attained the levels of CSO and separate stormwater control called for in the LTCP. While numerous LTCPs nationwide have been completed, and recommended CSO control projects implemented, there is less industry experience with the conduct of successful post-construction monitoring programs. Accordingly, the NDB Tunnel performance assessment approach was developed based on original and creative thinking about how to best demonstrate that the operational tunnel system was meeting LTCP requirements. This presentation will be of benefit to others preparing to conduct LTCP post-construction assessments. For the NDB Tunnel system, performance was assessed using data collected by tunnel system instrumentation and logged in the MWRA SCADA system. Data were available following start-up of tunnel system operation in May 2011. December 2018 was the data cut-off date, providing over 7 Â½ years of data for review. As a first step, MWRA rainfall summary records were reviewed to identify larger storm events, those with approximately a 1-year recurrence interval or larger. A total of 19 storm events meeting this size criterion were identified. Specific data to be obtained from the SCADA system were identified by reviewing tunnel system record drawings, the Operation and Maintenance (O&M) Manual, and a NDB tunnel control strategy document developed and used by MWRA for tunnel system operation. The MathWorks computational software package MATLAB was used to process SCADA system data and generate plots for system assessment. A total of 17 plots were prepared and inspected for each of the 19 storm events. Each plot was inspected to compare measured (SCADA) data to physical system characteristics such as CSO liquid level versus overflow weir height at a tunnel overflow point. Plots were also inspected to review operational decisions, such as operation of the pump station used to empty the tunnel after storm events and maintain capacity for storage during subsequent storms. Over 300 total plots were inspected to assess overall tunnel system performance and operation. Nearly all plots prepared and inspected exhibited consistent and appropriate tunnel system performance for each location. A few of the plots did not exhibit data fully consistent with expected performance. A listing of the storm event dates and locations for this subset of plots was prepared and reasons for observed inconsistencies were assessed. Most of these minor inconsistencies were explained by normal sensor or SCADA system outages. For example, in locations where redundant level elements are installed, differences in level measured by the two sensors account for some of the minor inconsistencies. Several plots showed fluctuations in levels indicative of tide gates not seating properly. Findings indicative of minor inconsistencies were relayed to MWRA so inspections could be scheduled to investigate and take corrective action as appropriate. As noted above, the NDB Tunnel system performance assessment is complete and has demonstrated that this marquee project, constructed to improve water quality along the South Boston Beaches, has met its design goals based on documented performance during storm events.

This paper was presented at the WEF Collection Systems Conference in Detroit, Michigan, April 19-22.

SpeakerHeath, Gregory

Presentation time

10:15:00

10:45:00

Session time

8:30:00

11:15:00

Session number13

Session locationHuntington Place, Detroit, Michigan

TopicCombined Sewer System, Post-Construction Monitoring, tunnels

Author(s)

G. Heath

Author(s)G. Heath1; D. Braz2; J. Hall3

Author affiliation(s)WEF Member Account1; AECOM2; Massachusetts Water Resources Authority3

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Apr, 2022

DOI10.2175/193864718825158330

Volume / Issue

Content sourceCollection Systems

Word count10

Base text size -

Heath, Gregory

About Heath, Gregory

My Recent Activity