Item 4E Memo - FINAL Item 4E
M E M O R A N D U M
(August 21, 2018)
To: Shana Yelverton, City Manager
From: Rob Cohen, Director of Public Works
Subject: Approve an annual purchase agreement for providing odor
control treatment at City wastewater lift stations with Premier
Magnesia, LLC. in an amount not to exceed $140,000 for a 12-
month period
Action
Requested: Approve an annual purchase agreement for providing odor control
treatment at City wastewater lift stations with Premier Magnesia,
LLC. in an amount not to exceed $140,000 for a 12-month period.
Background
Information: The City pre-treats the wastewater flows at the Shady Lane and
Lonesome Dove wastewater lift stations before it flows to the Trinity
River Authority (TRA) treatment plant. These two lift stations are
the largest in the City and handle the largest volume of wastewater
flows. The pre-treatment with Thioguard is necessary for several
reasons including 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. Treating with Thioguard
provides odor control that would otherwise have an impact on
residents. Hydrogen sulfide gas is also highly corrosive to concrete
manholes and the cast iron manhole ring and lid. Pre-treatment
with Thioguard aids in the reduction of hydrogen sulfide gas in
order to maintain the integrity of wastewater infrastructure. Premier
Magnesia has been providing Thioguard for Southlake and the
Trinity River Authority since 2006 because previous attempts to
control the hydrogen sulfide with other products were not
successful.
An additional benefit to this technology is the prevention of grease
buildup in the wastewater lift station wet-wells and downstream
sewer mains. This chemical treatment eliminates the need for City
crews to remove and dispose of excess grease. Grease causes
blockage in the mains that may lead to potential sewer overflows
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and Texas Commission on Environmental Quality (TCEQ) fines.
TRA also charges the City a surcharge for high levels of BOD
(Biochemical Oxygen Demand) attributed to grease in the
wastewater flows.
Last year it was necessary for the City to increase the Thioguard
dosing by 5-10 gallons per day at the Shady Lane Lift Station due
to the increase in the number of new restaurants in the City and the
subsequent increase in grease and BOD in wastewater flows.
Financial
Considerations:
Funding for odor control treatment at the City’s wastewater lift
stations is provided in the annual Public Works Wastewater
Operating Budget. Under the proposed agreement, the cost per
gallon will increase from $2.77 per gallon to $2.84 per gallon for the
upcoming year. Premier Magnesia is a sole source provider for
Thioguard technical grade magnesium hydroxide slurry.
Strategic Link: The annual purchase agreement for the magnesia treatment of
wastewater links to the City’s strategy map relative to the strategic
focus area of Performance Management and Service Delivery. The
specific corporate objectives that are met by this agreement
include: (B2) collaborate with select partners to implement service
solutions, and (F2) invest to provide and maintain high quality
public assets.
Citizen Input/
Board Review: N/A
Legal Review: N/A
Alternatives: The City Council may approve or deny the agreement.
Supporting
Documents: Attachment A: Premier Magnesia, LLC - Thioguard Annual Contract
Pricing
Attachment B: Premier Magnesia, LLC - Sole Source Letter
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Staff
Recommendation: Approve an annual purchase agreement for providing odor control
treatment at City wastewater lift stations with Premier Magnesia,
LLC. in an amount not to exceed $140,000 for a 12-month period.
Staff Contact: Rob Cohen, Director of Public Works
Cristina McMurray, M.P.A, C.P.M, Deputy Director of Public Works
6/14/18
Cristina McMurray
Deputy Director of Public Works - Operations
1950 East Continental Blvd
City of Southlake, Texas 76092
Re: Premier Magnesia, LLC – Thioguard® Annual Contract Pricing FY 2018-2019
Cristina:
Pursuant to your request for a renewal of the annual contract for Thioguard, I am submitting
this letter to update you on the terms of the agreement. You may submit Purchase Orders
either on a per load basis, or a Blanket PO may be issued for the duration of the price in effect.
The price per gallon for the upcoming year will be $2.84 effective July 1, 2018 through and
ending June 30, 2019.
At the current combined rate of usage for Lonesome Dove and Shady Lane of 120 - 130 gallons
per day, estimated annual costs are between $124,392 and $134,758 if the current BOD loading
to these stations stays constant. However, ongoing analysis points to a higher BOD level in the
collection system line that feeds Shady Lane, and consequently Round Hollow, which may result
in the need to feed additional chemical to treat these lines. In addition, rainfall events result in
more frequent and longer pump run times, which can affect the quantity of product fed.
Quarterly analysis of BOD levels continues to identify potential increases and required changes
to feed rates on a seasonal basis.
Premier Magnesia very much appreciates your cooperation and looks forward to a continued
long-term relationship as a quality supplier.
Sincerely,
Mary P. Evans
South Central Regional Account Manager
Premier Magnesia, LLC
Thioguard TST
Phone: 903.245.6316
20108 CR 186
Flint, Texas 75762
Email: mevans@premiermagnesia.com
Acceptance:
_________________________________________________________
Laura Hill, Mayor Date
Attested By:
_________________________________________________________
Carol Ann Borges, TRMC Date
City Secretary