Agenda Item Wording:
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Approve a contract amendment with Mike Clark Trucking - Approve an amendment to the contract with Mike Clark Trucking to increase the annual not-to-exceed amount from $226,800 to $331,800 to haul biosolids from the Visalia Water Reclamation Facility and appropriate an additional $273,000 from the Wastewater Fund.
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Prepared by:
Ben Litwack, Public Works Manager, 559-713-4671, ben.litwack@visalia.gov
Nick Bartsch, Public Works Director, 559-713-4052, nick.bartsch@visalia.gov
Department Recommendation: Staff recommends that Council approve an amendment to the contract with Mike Clark Trucking to increase the annual not-to-exceed amount from $226,800 to $331,800 to haul biosolids from the Visalia Water Reclamation Facility and appropriate an additional $273,000 from the Wastewater Fund (431) to cover the additional transport and disposal costs (disposal is covered in a separate contract).
Summary:
This action amends contract C25072 with Mike Clark Trucking to increase the not-to-exceed amount by $105,000, bringing the total to $331,800, and appropriates an additional $273,000 from the Wastewater Fund to complete disposal of the 2024 biosolids stockpile. Costs increased due to delayed hauling, longer haul distances to Lost Hills, higher moisture content from early rain events, increased loading from significant industrial users, and reduced digestion efficiency when one digester was offline for the first four months of 2024. As of this report, over 10,000 tons have been disposed of, with approximately 3,000 tons remaining, and hauling costs alone are about $30.50 per ton. Increased disposal costs are largely offset by penalties charged to industrial users, and future reductions are expected from improved pretreatment, new industrial agreements, and a 30% increase in drying bed capacity under the solids handling improvement project.
Background Discussion:
Contract No. C25072 provides hauling services through Mike Clark Trucking for the biosolids generated at the City of Visalia’s Water Reclamation Facility (WRF). In recent years, the volume of biosolids has increased primarily due to higher influent flows and organic loading from the City’s significant industrial users (SIUs). These increased loadings have resulted in higher biosolids production requiring increased drying, hauling, and disposal.
The 2024 biosolids stockpile was further impacted by operational and logistical challenges. One of the WRF’s digesters was offline during approximately the first four months of 2024, reducing the amount of biological stabilization normally achieved and limiting the breakdown of solids. This resulted in heavier, less-degraded biosolids and contributed to a larger overall stockpile.
Additionally, the Tulare County Landfill, the City’s previous disposal site, provided short notice at the end of May that it could only accept 200 tons of biosolids per month. This significantly reduced disposal capacity and required staff to identify a new disposal facility. Difficulties in procuring quotes and the time required to complete the City’s procurement process delayed the selection of a new site, and as a result, most hauling activities did not begin until late September.
The new disposal site selected, operated by Holloway Environmental Services in Lost Hills, California, is significantly farther from the WRF, increasing hauling time and cost. Hauling services provided by Mike Clark Trucking are billed at $135 per hour, and the extended round-trip time results in an approximate hauling cost of $30.50 per ton, exclusive of disposal fees.
Compounding these issues, Visalia experienced sporadic rain events and colder temperatures beginning in October and continuing through November and December. These conditions increased the moisture content of the biosolids stockpile, thereby increasing its overall weight and disposal cost. Rain events also required periodic pauses in hauling operations at the request of the disposal facility during major storm events.
Because biosolids piles are measured primarily by volume, and their weight fluctuates significantly with moisture content, predicting total disposal costs is inherently difficult. Each rain event increases the stockpile weight in an unpredictable manner. Additional moisture testing would require specialized consultants to collect representative samples from multiple locations within the pile, which would incur substantial additional cost and was not considered cost-effective.
As of the date of this staff report, more than 10,000 tons of biosolids have been hauled and staff estimates that approximately 3,000 tons remain.
While biosolids production has increased due to higher flows and organic loading from SIUs, these additional costs are largely offset through increased penalties and surcharges assessed to those users on their monthly utility bills. As a result, the financial impacts associated with higher biosolids volumes are borne primarily by the contributors of the increased loading, rather than by the general ratepayer.
Looking forward, staff anticipates improved conditions and reduced biosolids volumes as a result of increased pretreatment efforts and new agreements with major industrial users. The two SIUs have now installed their own pretreatment systems to reduce organic and solids loading discharged to the WRF, and these improvements are expected to begin producing measurable reductions in biosolids generation this year.
In addition, the WRF’s solids handling improvement project will increase drying bed capacity by approximately 30 percent. This added capacity will allow biosolids to remain in the drying beds for longer periods, reducing moisture content, total weight, and overall volume prior to hauling. This improvement will significantly reduce long-term hauling and disposal costs and increase operational efficiency.
Staff has also contracted with Carollo Engineers to design a 9th digester, which will provide increased firm capacity and detention time, leading to further breakdown of solids.
Amending Contract No. C25072 to increase the NTE by $105,000, bringing the total contract amount to $331,800, and appropriating an additional $273,000 from the Wastewater Fund will ensure adequate funding is available to complete the hauling and disposal of the remaining biosolids in a timely and compliant manner. Failure to approve this action could result in interruptions to hauling activities, extended onsite storage of biosolids, and increased operational and regulatory risk for the Water Reclamation Facility.
Fiscal Impact: Staff estimates there are 3,000 tons remaining of the 2024 stockpile. Staff anticipates hauling cost to be approximately $30.50 per ton, factoring in Mike Clark Trucking’s hourly rate, travel time, and load and disposal time. An additional $273,000 will need to be appropriated from the Wastewater Fund (431) into the biosolids operating budget in 4336-55700 to cover the hauling contract increase and the necessary increase in Holloway Environmental Services disposal contract.
Prior Council Action:
8/18/25: Council approved an amendment to increase the NTE of contract C25072 from $170,000 to $226,800.
Other: N/A
Alternatives: N/A
Recommended Motion (and Alternative Motions if expected):
recommendation
I move to approve an amendment to the contract with Mike Clark Trucking to increase the annual not-to-exceed amount from $226,800 to $331,800 to haul biosolids from the Visalia Water Reclamation Facility and the appropriation of $273,000 from the Wastewater Fund.
Environmental Assessment Status: N/A
CEQA Review: N/A
Deadline for Action: 2/2/2026
Attachments:
Contract C25072