HomeMy WebLinkAbout01.a. Approve minutes of meeting held 6-18-24Page 1 of 4
Item 1.a.
LCENTRAL SAN
July 11, 2024
FROM: KATIE YOUNG, SECRETARYOF THE DISTRICT
SUBJECT: JUNE 18, 2024 SPECIAL BOARD MEETING MINUTES
Attached are the draft minutes of the above Board meeting.
ATTACHMENTS:
1. Draft (Special) Board Minutes 06-18-24
July 11, 2024 Special Board Meeting Agenda Packet - Page 4 of 41
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LCENTRAL SAN
MINUTES*
SPECIAL BOARD MEETING
Board Room
Tuesday, June 18, 2024
8:30 a.m.
DRAFT
Open Session — Board Room
ROLL CALL
BOARD OF DIRECTORS:
MARIAHN LAURITZEN
President
MICHAEL R. MCGILL
President Pro Tent
BARBARA D.HOCKETT
TAD J PILECKI
FLORENCE T WEDINGTON
A special meeting of the Board of Directors was called to order at 8:31 a.m. Secretary of
the District Katie Young called roll:
PRESENT. Members: Hockett, McGill, Pilecki, Wedington, Lauritzen
ABSENT.- Members: None
TOUR
Tour of the Membrane Aerated Biofilm Reactor Pilot (MABR), Aeration Basins
Diffuser Replacement, Phase 1 and Solids Handling Facility Improvements, Phase
1 A projects
Operations Optimizations Manager Nitin Goel reviewed the presentation included in
the agenda materials.
Member Pilecki stated that in the past, when operating the conventional secondary
treatment process at a higher solids retention time (SRT) for total inorganic nitrogen
(TIN) removal, a large amount of foam was created. He asked if Mr. Goel could
address how MABR will help control that issue.
In response to Member Pilecki's concern regarding foam, Mr. Goel responded that
an existing infrastructure retrofit and new facilities would include equipment to
remove foam and dispose of it in existing solids handling facilities.
In response to a question posed by Member Hockett regarding if the aeration basin
will be deeper, Mr. Goel explained that oxygen transfer efficiency depends on water
depth above diffusers and diffuser oxygen transfer efficiency. The new diffusers will
Book 72 — Page 79
July 11, 2024 Special Board Meeting Agenda Packet - Page 5 of 41
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CENTRAL CONTRA COSTA SANITARY DISTRICT
June 18, 2024 Special Board Meeting Minutes - Book 72-Page 80
be at a similar water depth to the existing diffusers. However, they will achieve a
much better oxygen transfer efficiency compared to existing aged diffusers.
Deputy General Manager — Engineering and Operations Greg Norby further
explained that while the aeration basin volume is not changing, the improved
aeration system will be significantly more efficient and more easily optimized.
In response to a question posed by Member Hockett about potential increased
capacity for ultraviolet (UV) disinfection, Mr. Goel responded that there is a current
limit of 100 Million Gallons Per Day (MGD) through the UV disinfection system, but
the new facility will have a capacity of 140 MGD.
In response to a question regarding the location of the MABR, Mr. Goel advised that
the MABR could be added inside numerous existing tanks. The MABR could help
achieve nitrification and denitrification process and efficiency can be controlled by air
scouting. Member Pilecki stated that the membranes will only be in the upper 2/3rds
of the tank water depth and Mr. Goel confirmed that statement was correct.
Mr. Goel stated that the primary objective of the pilot project is to figure out how
much TIN reduction can be achieved in existing tanks and the associated costs. The
MABR biofilm at the current feed location of secondary clarifier influent is
successfully converting ammonia into nitrate. However, to achieve TIN reduction, the
nitrate must be converted to nitrogen gas, which requires soluble carbon. This may
be achieved at a future pilot project feed location. Mr. Goel stated that incomplete
nitrification could increase the risk of nitrous oxide production, which is a high impact
greenhouse gas. He stated that the project seeks to optimize TIN reduction without
sacrificing air quality.
The Board Members and other attendees present were then escorted on a tour of
the facilities involved in the projects and no decisions or actions were made or taken
by the Board of Directors during the tour.
ADJOURNMENT
The meeting was adjourned at 10:35 a.m.
Mariah N. Lauritzen
President of the Board of Directors
Central Contra Costa Sanitary District
County of Contra Costa, State of California
July 11, 2024 Special Board Meeting Agenda Packet - Page 6 of 41
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CENTRAL CONTRA COSTA SANITARY DISTRICT
June 18, 2024 Special Board Meeting Minutes - Book 72-Page 81
COUNTERSIGNED:
Katie Young, CPMC, CIVIC
Secretary of the District
Central Contra Costa Sanitary District
County of Contra Costa, State of California
July 11, 2024 Special Board Meeting Agenda Packet - Page 7 of 41