Section 465.390  General Quality Control Procedures

a)         A written description of the current laboratory quality control program shall be maintained and made available to analysts in an area of the laboratory where analytical work takes place.  A record of analytical quality control tests and quality control checks on media, materials, and equipment shall be prepared and retained for 5 years.

b)         A laboratory manual containing complete written instructions for each parameter for which the laboratory is certified shall be maintained and made available to analysts in an area of the laboratory where analytical work takes place.

c)         The following minimum requirements shall apply to analytical quality control tests for general laboratory practices and methodology:

1)         Verify all coliform colonies.  However, if the number of colonies exceeds 10/100 ml, then randomly pick 10 colonies for verification.  An acceptable alternative method is to swab the entire membrane surface and transfer the swab to the verification test media in the following order: lauryl tryptose broth, EC medium, brilliant green lactose broth.

2)         A start and finish membrane filtration control test of rinse water, media, and supplies shall be conducted for each filtration series.  If sterile controls indicate contamination, all data on samples affected shall be rejected and a request made for immediate resampling of those waters involved in the laboratory error.

3)         When unknown performance evaluation samples are available, each approved analyst shall analyze at least one per year for the parameters measured.  When performance evaluation sample results indicate technical error, the  Department will provide appropriate technical assistance to determine the cause and make suggestions for correction of the problem.

4)         Each analyst approved for the total coliform procedure by the membrane filter technique shall verify quarterly total coliform analyses by swabbing 3 plates from a known positive sample and inoculating lauryl tryptose broth and brilliant green lactose bile broth from each plate.  The lauryl tryptose broth and brilliant green lactose bile broth shall be incubated at 35.0º + 0.5º C for 24 to 48 hours.  Turbid growth with gas production indicates a positive result.

5)         Each analyst approved for EC verification shall inoculate quarterly 3 tubes of EC medium with the same swabs used to perform the quarterly total coliform verification.  EC medium shall be incubated at 44.5º + 0.2º C for 24 hours.

6)         Each analyst approved for the fecal coliform procedure by the membrane filter technique shall verify quarterly fecal coliform analyses by picking at least 10 isolated colonies from membranes containing typical blue colonies and transferring to lauryl tryptose broth and EC medium.  The lauryl tryptose broth shall be incubated at 35.0º + 0.5º C for 24 to 48 hours.  The EC medium shall be incubated at 44.5º + 0.2º C for 24 hours.  Turbid growth with gas production indicates a positive result.

7)         If there is more than one analyst in the laboratory, at least once each quarter each analyst shall count the same heterotrophic plate count plate, total coliform membrane, and fecal coliform membrane (if appropriate).  Colony counts between analysts shall agree within 10 percent.

8)         The standards for laboratory pure water specified in Section 465.380 shall be met.