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Statement of Work - Enzyme Substrate Coliform Test Media 2 Municipal Laboratory, Environmental Services and Sustainability Department 1056 S. Mayhill Rd. Denton, Texas 76208 8563 Enzyme Substrate Coliform Test Media STATEMENT OF WORK Date Prepared: 5/1/2024 Presenter Name: Marcos Diosdado City of Denton Statement of Work 2 | P a g e Name of Project: 8563 Enzyme Substrate Coliform Test Media 1.0 Introduction/Background The City of Denton Municipal Laboratory (Laboratory) was recognized and accredited in accordance with the National Environmental Laboratory Accreditation Program (NELAP) and the Texas Water Code Chapter 5, Subchapter R, Title 30 Texas Administrative Code Chapter 25 to provide testing services for Heterotrophic Plate Count (The NELAC Institute, TNI analyte 2555, TNI method 20180001) and Total Coliforms & Escherichia coli (E. coli) presence/absence (TNI analyte 2502, TNI methods 20212413 & 20214602) for drinking water in 2009. The Laboratory expanded its accreditation in 2017 to include E. coli & Total Coliforms enumeration in drinking water (TNI analytes 2525 & 2500, TNI method 20211603) and E. coli enumeration (TNI analyte 2525, TNI methods 60002600 & 20212800) in non-potable water. The Laboratory requires the use of an Enzyme Substrate Coliform Test Media (Media) that is suitable for use in testing potable and non-potable waters. The Laboratory processes samples and reports results to regulatory agencies for over 170 external customers and four internal customers. 2.0 Objectives The City of Denton is interested in receiving proposals from prospective suppliers to provide enzyme substrate coliform test media, sample vessels (bottles and multi-well enumeration trays), tray sealer, and results comparators to continue sustaining the current customer testing needs and to accommodate future increases. Results generated by the Laboratory are used by internal and external customers to meet their regulatory requirements under the Revised Total Coliform Rule (RTCR) using test methods approved under the Code of Federal Regulations Title 40 Part 141 (40 CFR 141) and National Pollutant Discharge Elimination System (NPDES) permits using test methods approved under the Code of Federal Regulations Title 40 Part 136 (40 CFR 136). The Laboratory seeks to continue providing testing services to its internal and external customers under NELAP (National Environmental Laboratory Accreditation Program) standards for drinking water and non-potable water. 3.0 Scope of Work Media and multi-well enumeration trays must be approved for compliance testing of Total Coliforms and E. coli in drinking water under 40 CFR 141 and for compliance testing of E. coli in wastewater under 40 CFR 136 using the Standard Methods 9223B procedure. Media must pass quality control and performance checks for sterility, selectivity, sensitivity, growth promotion, and growth inhibition as outlined in The NELAC Institute Standard (2016), Volume 1, Modules 2 & 5. Media and vessels must pass quality control testing (QC) as outlined in Standard Methods 9020 and 9223B and the TNI Standard (2016), Volume 1, Modules 2& 5. Media must be packaged in individual portions, suitable for direct use in 100 mL of sample. City of Denton Statement of Work 3 | P a g e Sample vessels must be suitable for the direct addition of media and incubation. Enumeration trays must be suitable for direct incubation in a circulating air incubator and by submersion in a water bath. All media, sample vessels, and enumeration trays must be assigned a lot number traceable to the Certificate of Analysis (COA). 3.1 Media Specifications The Laboratory requires a medium with a 24 – 28-hour incubation time and a medium with an 18 – 22-hour incubation time. • Media must exhibit a color change to indicate the presence of total coliforms. • Media must exhibit fluorescence to indicate the presence of E. coli under a long wavelength (365 – 366 nm) ultraviolet lamp. • Media must be able to detect one colony-forming unit (CFU) in a 100 milliliter (mL) sample. • Media must be able to suppress heterotrophic growth up to 2 million heterotrophs per 100 mL. • Media must simultaneously detect total coliforms and E. coli without requiring a confirmation step. • Media must be suitable to use in multi-well trays and have capacity of producing a most probable number (MPN) result for total coliforms and E. coli of at least 2,419 for 100 mL of undiluted sample. • Individual media packets must be assigned and marked with a unique lot number traceable to the COA. 3.2 Sample Bottle Specifications The Laboratory requires sample bottles in two volume sizes, 120 mL and 290 mL. The 120 mL bottles must have a 100 mL gradation. The 290 mL bottles must have 100, 200, and 250 mL gradations. Sample bottles must pass quality control checks for sterility, pH, auto- fluorescence, chlorine neutralization, and volume. • Sample bottles must show to be sterile using non-selective growth media after a 48- hour incubation period at 35 ± 0.5°C. • Must show to be at a circumneutral pH using bromothymol blue. • Must lack auto-fluorescence under a long wavelength (365 – 366 nm) ultraviolet lamp. • Volume gradations must show to be within ± 2.5 mL of stated volume using a gravimetric method. • Must contain enough sodium thiosulfate to neutralize at least 15 mg/L of chlorine per 100 mL of sample. • Must have a tamper-evident shrink band seal. • Individual bottles must be assigned and marked with a unique lot number traceable to the COA. 3.3 Multi-well Sample Tray Specifications The laboratory requires multi-well sample trays capable of partitioning 100 mL of sample to provide results for total coliforms and E. coli of at least 2,419 MPN per 100 mL of undiluted sample. City of Denton Statement of Work 4 | P a g e • Trays must show to be sterile using non-selective growth media after a 48-hour incubation period at 35 ± 0.5°C. • Must show to be at a circumneutral pH using bromothymol blue. • Must lack auto-fluorescence under a long wavelength (365 – 366 nm) ultraviolet lamp. • Must be able to remain sealed during the incubation period without allowing individual wells to merge or leak into another. • Each case/box of enumeration trays must be assigned and marked with a unique lot number traceable to the COA. 3.4 Multi-well Sample Tray Sealer Specifications The laboratory requires a multi-well sample tray sealer capable of permanently heat-sealing trays containing 100 mL of a sample without allowing individual wells to merge or leak into another. • Must be able to seal trays containing 100 mL of sample at 4°C. • Must not raise the temperature of the temperature of the sample in the wells more than 5°C. 3.5 Comparators The laboratory requires comparators to accurately determine test results. Comparators must show the minimum color threshold for total coliforms and fluorescence threshold for E. coli that determines a positive result for each media type. Comparators must have the same volume and be the same type of container as the sample vessels. 4.0 Vendor Requirements Vendor must make accessible online or provide printed copies of applicable Safety Data Sheets. Vendor must make accessible online or provide printed copies of applicable Certificates of Analysis that are traceable to lot numbers of all media, sample vessels, and enumeration trays. Vendor must give a 45-day advanced notice of any changes in materials that could have an effect on the performance or suitability of the media, vessels, comparators, and related equipment. 5.0 Price Structure Vendor’s proposal must specify the proposed pricing structure. Pricing structure should include unit pricing, quantity price breaks, pricing breaks for supplies bought as combination packs or sets, and projection of expected pricing increases for the life of the contract. City of Denton Statement of Work 5 | P a g e 6.0 Evaluation Procedure: 6.1 Compliance with Specifications (Factor: 40%) Approval under the Code of Federal Regulations and compliance with the stated specifications is critical due to regulatory and certification requirements. Prospective vendors must be able to show approval of proposed media under the CFR. Media, vessels, and enumeration trays must meet the stated specifications. Prospective vendors must make accessible online or provide printed copies of applicable Safety Data Sheets. Vendor must make accessible online or provide printed copies of applicable Certificates of Analysis that are traceable to lot numbers of all media, sample vessels, and enumeration trays. 6.2 Overall Experience and Performance (Factor: 20%) Overall evaluation of the history of the vendor, experience as it relates to the requirements for this proposal, evidence of past performance, and demonstrated quality of products and services. Extent and previous experience providing services to government organizations under NELAP or similar certification. 6.3 Price and Projected Price Increase (Factor: 40%) Consideration of proposed vendor pricing structure, unit costs, and quantity price breaks. This will include consideration of projected pricing increases.