Analytical methods for surface water source water monitoring

Analytical methods for surface water source water monitoring. (1) Cryptosporidium. Water suppliers shall analyze for Cryptosporidium using Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA–815-R–05–002 or Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA–815–R–05–001. The water supplier may obtain a copy of these methods online from http://www.epa.gov/safewater/disinfection/lt2 . Water suppliers may also use EPA Method 1623.1: Cryptosporidium and Giardia in Water by Filtration/IMS/FA , 2012. EPA-816-R-12-001. (Available at http://water.epa.gov/drink . ) (a) Water suppliers shall analyze at least a 10 L sample or a packed pellet volume of at least 2 mL as generated by the methods listed in this subsection. Water suppliers unable to process a 10 L sample shall analyze as much sample volume as can be filtered by two filters approved by EPA for the methods listed in this subsection, up to a packed pellet volume of at least 2 mL. (b) Matrix spike (MS) samples, as required by the methods in this subsection, shall be spiked and filtered by a laboratory approved for Cryptosporidium analysis under s. NR 809.335 . If the volume of the MS sample is greater than 10 L, the water supplier may filter all but 10 L of the MS sample in the field, and ship the filtered sample and the remaining 10 L of source water to the laboratory. In this case, the laboratory shall spike the remaining 10 L of water and filter it through the filter used to collect the balance of the sample in the field. (c) Flow cytometer-counted spiking suspensions shall be used for MS samples and ongoing precision and recovery (OPR) samples. (2) E. coli . Water suppliers shall use methods for enumeration of E. coli in source water listed in Table I. (a) The time from sample collection to initiation of analysis may not exceed 30 hours unless the condition of par. (b) are met. In all cases, samples should be analyzed as soon after collection as possible. (b) The department may approve on a case-by-case basis the holding of an E. coli sample for up to 48 hours between sample collection and initiation of analysis if the department determines that analyzing an E. coli sample within 30 hours is not feasible. E. coli samples held between 30 to 48 hours shall be analyzed by the Colilert reagent version of Standard Method 9223B as listed in sub. (2) , Table I. (c) Water suppliers shall maintain samples between 0 ° C and 10 ° C during storage and transit to the laboratory. (3) Turbidity. Water suppliers shall use methods for turbidity measurement under s. NR 809.113 (1) Table A.