Analysis of Protozoa in Groundwater

2026-11-03

The Minnesota Department of Health ( MDH ) requests proposals from environmental laboratories for the analysis of Minnesota public water supply groundwater sources to implement analyses of Cryptosporidium and Giardia . MDH is responsible under 40 CFR 142 . 16 ( b )( 2 )( i )( B ) for identifying public water supply groundwater sources that are under the direct influence of surface water ( GWUDI ). These sources need to be identified to protect the public from microbial contaminants including Cryptosporidium and Giardia . Sample Tasks and Deliverables . Microbial Filters , Sample Receiving , and Return of Sample Shipping Containers . The Contractor will provide all new pre ‐ certified Elisio 25H ultrafilters with proper preservatives , labels , corresponding chain of custody forms and packing material for each sample requested . Each individual filter will be labeled with a lot and serial number for tracking purposes . The delivery of filters and associated materials will be coordinated in advance with the Minnesota Department of Health ( MDH ) sampling personnel . The State anticipates an average of 20 – 40 samples will be submitted quarterly during the period and up to 40 samples for investigative or follow - up purposes through March 2027 . The Contractor will coordinate with the State ’ s sampling personnel to ship filters and associated materials via a commercial courier . All costs associated with shipping of filters and associated material will be the responsibility of the Contractor . The Contractor will also be responsible for next day shipping costs related to submitting filters and associated materials to the laboratory , as well as shipping costs associated with the return of the shipping containers . Contractor will initiate the sample login process once the sample filters arrive at the contract laboratory . This includes verifying the sample filter integrity and the accompanying chain of custody documentation as well as recording the temperature . Samples that are not collected the same day they are received and that are received at greater than 20 degrees Celsius or frozen must be rejected . Any discrepancy encountered will be communicated to the designated State Project Manager as soon as possible . Upon receipt , the Contractor will sign the Chain of Custody ( COC ) document , taking custody of the sample filters and store them in an appropriate secured location . Samples will then be entered into the Contractor ’ s Laboratory Information Management System ( LIMS ), where a unique identification number is assigned to each sample filter . After the samples are logged into the LIMS , a sample receipt acknowledgement will be generated and sent via email to the State Project Manager for review . Microbial Analysis and Methods The Contractor will perform microbial analysis based on EPA method 1623 with modifications for tangential flow hollow - fiber ultrafiltration and heat dissociation steps as per Rhodes et al ., 2012 ( A Modified EPA Method 1623 that Uses Tangential Flow Hollow - fiber Ultrafiltration and Heat Dissociation Steps to Detect Waterborne Cryptosporidium and Giardia spp - PMC ). Analysis will consist of two target analytes : Cryptosporidium and Giardia . Any deviations from the methods , that are necessary based on lab capabilities , must be pre - approved by the State ’ s Authorized Representative or State ’ s Project Manager in advance . All sample analyses will be performed at the contract laboratory by Analysts or Principal Analysts as defined in Method 1623 and all appropriate Quality Assurance and Quality Control ( QAand QC ) practices will be followed . After analysis , the Contractor will perform a secondary review of the QC requirements and acceptance criteria outlined in Tables 3 and 4 of Method 1623 ( https :// www . epa . gov / sites / default / files / 2015 - 07 / documents / epa - 1623 . pdf ). If a discrepancy is noted , the package will be returned to the Contractor ’ s primary analyst for corrective action . Once the analytical batch is reviewed and evaluated , the Contractor ’ s Project Manager will perform a final review of the results and release the data for reporting . The analytical report consists of the final results , any relevant quality control data , and a copy of the chain of custody document . Holding Time . The Contractor will perform analysis of all microbial samples as soon as possible but sample filters may be stored between 1 degree Celsius and 10 degrees Celsius for up to 96 hours from collection prior to elution . All hold times outlined in Section 8 . 2 and Table 1 of Method 1623 ( https :// www . epa . gov / sites / default / files / 2015 - 07 / documents / epa - 1623 . pdf ) must be met . All sample analysis completed after the holding times specified above must be approved by the State ’ s Authorized Representative or the State ’ s Project Manager in advance . Reporting Requirements and Electronic Data Submittal .

Minnesota

2026-05-02