011310 Acceptance-Rejection criteria for Water Bactriology tests




1100 W. 49th Street • Austin, Texas 78756
P.O. Box 149347 • Austin, TX 78714-9347
1-888-963-7111 • http://www.dshs.state.tx.us
963TDD: 1-800-735-2989




January 13, 2010


Dear Submitter,

Effective January 1, 2010, the Texas Department of State Health Services (DSHS), Laboratory Services Section, will be enforcing more stringent acceptance/rejection criteria for the Water Bacteriology tests to include the detection of excessive chlorine levels in addition to the presence of total coliforms and E. coli in drinking water. These changes will ensure compliance with 2003 National Environmental Laboratory Accreditation Conference (NELAC) Standard a. Please follow the critical steps below to ensure accurate test results. Detailed instructions are attached. (pdf_icon 17kb)

  • Please submit a completed G-19 submission.
  • General collection and submission guidelines can be found at our website http://www.dshs.state.tx.us/lab/mic-cm_collect.shtm
  • Fill the bottle with the water to the neck of the bottle. Do not overfill or under fill. Do not let the water over flow. A sample level below 105 milliliters renders the sample unsuitable for analysis due to insufficient quantity.
  • The tablet inside the bottle is designed to inactivate a minimum of 20 parts per million of chlorine. A sample may be declared unsuitable for analysis for excessive chlorine if the chlorine residual is found in the sample.
  • When a sample is collected, leave ample air space in the bottle (at least 2.5 cm) to facilitate mixing by shaking, before examination. A sample judged to have too little air space may be unsuitable for analysis for being too full to permit sufficient agitation.
  • Please do not deliver or ship packages to arrive on Saturday or on a federal holiday.

Any samples that do not meet these criteria upon receipt will be considered unsatisfactory for testing and will be immediately discarded.

If you have any questions, please contact Monica Kingsley, Consumer Micro Team Supervisor at 512-458-7562 orvia email.


Susan U. Neill, PhD, MBA
Director, Laboratory Services Section

Last updated January 21, 2011