Biology - Laboratory Capabilities
TABLE OF CONTENTS
I. EPA Method 1623
II. Total Coliform
III. HPC ( Heterotrophic Plate Count)
IV. Fecal Coliform
Summary
The TMWA Water Quality (WQ) Laboratory located at the Glendale Water Treatment Plant is capable of collecting and analyzing samples for bacterial and protozoan contaminants in both raw and finished waters serviced in the Reno/Sparks area. This document summarizes the microorganisms that the WQ lab is capable of identifying.
I. EPA Method 1623 Identification of Giardia lamblia and Cryptosporidium
The TMWA Water Quality Laboratory analyzes both treated and untreated water samples for Giardia lamblia cysts and Cryptosporidium oocysts. Sampling occurs at two locations, the Chalk Bluff Water Treatment Facility and at the Glendale Water Treatment Facility. EPA method 1623 requires filtration of both processed and unprocessed water, immunomagnetic separation of the oocysts and cysts from the other material captured, and the use of an immunofluorescence assay for determination of oocyst and cyst concentrations. Confirmation is completed through vital dye staining and differential interference contrast (DIC) microscopy.
II. Total Coliform Analysis
Coliform bacteria are used as an indicator organism to identify possible contamination of a water sample. The membrane filter method is used at the TMWA Water Quality Lab to verify the presence or absence of Coliform bacteria. The membrane filter method consists of filtering a 100mL sample followed by placing the filter on a growth enrichment media (mEndo) and incubating it for 24 hours at 35.0 degrees Celsius. Coliform bacteria are identified by a gold-green sheen present on the filter after incubation.
III. HPC (Heterotrophic Plate Count)
The TMWA Water Quality lab is certified to processes system samples for an estimate of the total bacterial population in the water. The Heterotrophic Plate Count (HPC) is a laboratory procedure that is used to estimate the total bacterial count present in a given water sample. HPC's are performed by placing one milliliter of water diluted in a Standard Methods agar gel, the samples are incubated for 48 hours at 35 degrees Celsius and any colonies that grow during this time are counted.
IV. Fecal Coliform Analysis
Fecal coliforms are bacteria of the coliform group that are indicative of fecal contamination. The Water Quality Laboratory at the Glendale Water Treatment Plant is certified to test for the presence of fecal coliforms. The membrane filter method is also used in the identification of Fecal Coliform bacteria. 100mL of sample water is filtered and placed on a selective growth media, placed in a waterproof plastic bag and incubated in a water bath at 44.5 degrees Celsius for 24 hours.
