City Council
Report
City Council Meeting: July 12, 2022
Agenda Item: 5.G
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To: Mayor and City Council
From: Rick Valte, Public Works Director, Public Works, Office of Sustainability & the Environment
Subject: Approval of First Modification to Agreement #11181 with Montrose Environmental for additional Operation, Maintenance, and Monitoring of the Landfill Gas Management System
Recommended Action
Staff recommends that the City Council authorize the City Manager to negotiate and execute a first modification to agreement #11181 in the amount of $300,000 with ES Engineering Services DBA Montrose Environmental for the operation, maintenance, and monitoring of the Landfill Gas Management System for the Public Works Department.
This will result in a five-year amended agreement with a new total amount not to exceed $1,015,211, with future year funding contingent on Council budget approval.
Summary
The City has continuously operated a landfill gas extraction (LFG) and treatment system since 1998 to monitor methane levels and to maintain safe environmental conditions for the nearby Pico Neighborhood residents, Gandara park users, and City staff who work at the Municipal Yards. Oversight of the LFG is performed by a licensed independent contractor, ES Engineering Services DBA Montrose Environmental, who maintains, operates, and manages the LFG system in strict accordance with permits from the County of Los Angeles’ Department of Health Services (DHS) and the South Coast Air Quality Management District (SCAQMD). The permits require routine monitoring and maintenance of a perimeter probe network, ambient air quality above the landfill, and control system operation. Compliance reports are submitted to the DHS and SCAQMD on a quarterly basis. In June of 2021, the City conducted a competitive selection process and entered into an agreement with ES Engineering Services DBA Montrose 2 of 5
Environmental for routine maintenance and operation of the LFG system. City staff have identified additional operational, maintenance, and monitoring needs to keep the LFG system running efficiently and effectively. This new work is additive to the original scope of services that was approved by Council in 2021. In order for the City to complete system enhancement projects, staff is recommending amending the existing agreement with ES Engineering Services DBA Montrose Environmental.
Discussion
The City has been actively monitoring methane levels at the former landfill site since 1996. California Title 27 regulations for control of LFG adopted in 1997 required an LFG Control System to be installed to control gases generated by the decomposition of the landfill material. An interim LFG Control System was installed in 1998 and construction of a permanent LFG Control System was completed in the fourth quarter of 2000.
The objectives of the LFG Control System are:
• Reduce methane concentrations within the landfill;
• Reduce methane concentrations in native soils surrounding the landfill; • Reduce methane concentrations in identified utility trenches; and • Maintain methane concentrations in perimeter subsurface detection probes outside the landfill below the regulatory action level of five percent methane by volume or 50,000 parts per million.
Over the past 24 years, the LFG has observed predominantly safe methane levels in all of the system’s 37 sub-surface probe monitors, including a network of monitoring probes and gas extraction wells that specifically monitor methane levels adjacent to the Mountain View Mobile Home Park. This record demonstrates that methane levels – both underground and in the ambient air environment – are generally below the regulatory compliance threshold of 5%, with a few isolated exceptions. Overall, the site generates a low volume of methane. This can be attributed to the landfill being over 50 years old and to the composition of the waste landfilled, which was predominantly construction 3 of 5
debris such as concrete blocks, bricks, and wood. Based on the volume and type of waste in place and the known time the landfill was in operation, landfill modelling indicates that the landfill’s current ability to generate methane is very low and will continue to decrease over time due to the low levels of organic materials buried in the landfill.
Today, landfill gas levels remain relatively stable at the former landfill site; however, some anomalies have been recorded at a handful of locations within the Municipal Yards that exhibit temporary increases in methane levels and momentarily exceed the regulatory threshold. These anomalies are believed to be caused by excess moisture in the landfill due to above average rainfall, a main water line that leaked into the subsurface soil, and site construction activities over the past year. Increased moisture and saturation of organic materials increases the production of methane via methanogenesis (anaerobic digestion). These temporary increases can be remedied by adjustments to the LFG mechanical network and/or through expansion of the control system. Hence, Public Works is proposing to add additional scope to the ES Engineering Services DBA Montrose Environmental contract beyond the routine maintenance and monitoring of the LFG system to include the following enhancement activities:
• Install vertical extraction well LFG-11 and trench including permits, plans, labor, travel, FID monitoring, all materials and equipment, waste management and final report;
• Install vertical extraction well LFG-12 and trench including permits, plans, labor, travel, FID monitoring, all materials and equipment, waste management and final report;
• Install 25 hp blower & motor including obtaining permits, labor, travel, all materials and equipment;
• Install a new Alarm Call Out system, upgrade control panel and run new conduit and wires, install float sensor on entrainment tank and wire high level sensors to control panel. Includes obtaining permits, labor, travel, all materials and equipment; and
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• Raise probes PP-5R, PP-14 and header access vault for accessibility.
If approved, Public Works, through ES Engineering Services DBA Montrose Environmental, would need to prepare and submit applications and obtain permits from the LACDPH and SCAQMD for the installation of the new wells and all necessary trenching and piping connections to the original system. In addition, the City would need to prepare a Workplan and Health & Safety Plan to monitor all construction activities at the site during installation of the new mechanical equipment.
Past Council Actions
Meeting Date Description
10/26/2021
(attachment A)
Landfill Gas Study Session
7/27/2021
(attachment B)
Original RFP bid and award of agreement with ES
Engineering Services DBA Montrose Environmental for
services related to the operation, maintenance, and
compliance sampling and reporting for the City’s Landfill Gas Control System
Financial Impacts and Budget Actions
Staff seeks authority to approve funding from the General Fund to increase the amount of contract with ES Engineering Services DBA Montrose Environmental for services related to the operation, maintenance, and compliance sampling and reporting for the City’s Landfill Gas (LFG) Control System. Funds are available in the FY 2022-23 Capital Improvement Program Budget for this project.
Contract Request
Agreement
#
Current
Authorized
Amount
FY 2022-23
Modification
Request
Amount
Dept/CIP Account #
Total Revised
Contract
Amount
11181 $715,211 01500020.550010 $715,211
11181 $300,000 C0104580.689000 $300,000
$715,211 $300,000 Total $1,015,211
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Prepared By: James Velez-Conway, Senior Sustainability Analyst Approved Forwarded to Council
Attachments:
A. 4576 LFG Study Session
B. Executed-ES_Engineering_Contract_Sept_2021.docx
C. Santa Monica LFG Wells & System Upgrades Proposal 20220615 D. ES Engineering Oaks Initiative Form MEG2-signed