Item 4G - MemoItem 4G
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M E M O R A N D U M
(June 20, 2023)
To: Shana Yelverton, City Manager
From: Rob Cohen, Director of Public Works
Subject: Approve an annual purchase agreement for providing odor
control treatment at the City’s wastewater lift stations with
Premier Magnesia, LLC. in an amount not to exceed $135,000
for a 12-month period.
Action
Requested: Approve an annual purchase agreement for providing odor control
treatment at the City’s wastewater lift stations with Premier
Magnesia, LLC. in an amount not to exceed $135,000 for a 12-month
period.
Background
Information: The City pre-treats the wastewater flows at the Shady Lane and
Lonesome Dove lift stations before it flows to the Trinity River
Authority (TRA) treatment plant. The pre-treatment with Thioguard is
necessary for controlling odor, maintaining infrastructure integrity,
breaking up grease, and managing treatment costs.
The City has to pre-treat the wastewater to manage the effects of
hydrogen sulfide gas in the sewer system. Hydrogen sulfide gas has
a very strong “rotten egg” odor and is highly corrosive to concrete
manholes and the cast iron manhole ring and lid. Treating with
Thioguard provides odor control that would otherwise have an impact
on residents. In addition, it aids in the reduction of said gas, so the
integrity of the wastewater infrastructure is not compromised.
Premier Magnesia has been providing Thioguard for Southlake since
2006 because previous attempts to control the hydrogen sulfide with
other products were not successful.
Another benefit to this technology is the prevention of grease buildup
in the wastewater lift station wet wells and downstream sewer mains.
Grease causes blockage in the mains that may lead to potential
sewer overflows and Texas Commission on Environmental Quality
(TCEQ) fines. Additionally, TRA charges the City a surcharge for
high levels of BOD (Biochemical Oxygen Demand) attributed to
grease in the wastewater flows. In utilizing this chemical treatment,
it eliminates the need for City crews to remove and dispose of excess
grease.
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Since 2017, the Wastewater and Environmental Services Divisions
have been working collectively to reduce the amount of grease that
enter the wastewater system. The FOG program was created to
address the large amount of grease that derive from food
establishments. The FOG Team coordinates with food
establishments within the City to educate them on the proper
maintenance of their grease trap. Through outreach, cooperation,
and enforcement of these food establishments, the cognizant
disposal of grease helps to reduce hydrogen sulfide levels in the
sanitary sewer system aiding in the reduction of Thioguard needed.
Financial
Considerations: Under the proposed agreement, the cost per gallon will increase from
$3.34 per gallon to $3.65 per gallon for the upcoming year due to the
cost in materials and delivery. Premier Magnesia is a sole source
provider for Thioguard technical grade magnesium hydroxide slurry.
The last four fiscal years, the cost per gallon for Thioguard has been:
• FY 2019, $2.84/gallon
• FY 2020, $2.91/gallon
• FY 2021, $3.25/gallon
• FY 2022, $3.34/gallon
In addition, in the last four fiscal years, the City has spent the
following with Premier Magnesia, LLC.:
• FY 2019, $73,162
• FY 2020, $89,818
• FY 2021, $101,773
• FY 2022, $110,300
Funding for providing odor control treatment at the City’s wastewater
lift stations is budgeted in the Utility Fund via the Wastewater
Operating budget.
Strategic Link: These items link to the City’s Strategy Map by delivering on the focus
area of Infrastructure & Development. It provides this by focusing on
B2: Collaborate with Select Partners to Implement Service Solutions,
and F2: Invest to Provide & Maintain High Quality Public Assets.
Citizen Input/
Board Review: None
Legal Review: None.
Alternatives: The City Council may approve or deny the agreement.
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Supporting
Documents: Attachment A: Premier Magnesia, LLC – Thioguard Annual Contract
Pricing
Attachment B: Premier Magnesia, LLC – Sole Source Letter 2023
Staff
Recommendation: Approve an annual purchase agreement for providing odor control
treatment at the City’s wastewater lift stations with Premier
Magnesia, LLC. in an amount not to exceed $135,000 for a 12-month
period.
Staff Contact: Rob Cohen, Director of Public Works
Jack Thompson, Deputy Director of Public Works – Operations