This open-concept area is where a majority of the laboratory work takes place.  The testing here is used to aid in efficient operation of the wastewater treatment plant, to comply with permit requirements and to bill our customers.  The main categories of tests conducted in this area are: Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), Fecal Coliform, Chloride, Cyanide and Residual Chlorine.

BOD
The biochemical oxygen determination measures the oxygen required for the biochemical breakdown of organic material and the oxygen used to oxidize inorganic material.  The lab analyzes BOD according to Standard Methods 5210. Dissolved oxygen readings are measured by an automated BOD reader called the BOD AutoEZ.  The AutoEZ consists of four DO probes which analyze four sample bottles at one time.  The instrument can analyze 36 bottles in less than 15 minutes.  The AutoEZ calculates the final results and reduces analyst time by over 50% compared to the manual technique.

TSS
The Total Suspended Solids test is used to measure the amount of solids dissolved or suspended in wastewater. Using Standard Methods 2540 D, a thoroughly mixed sample is filtered through a weighed crucible containing a glass fiber filter. This filter is dried to a constant weight at 103 to 105 degrees centigrade.  A sample is filtered, dried, desiccated and weighed to constant weight. .

COD
Chemical Oxygen Demand is used to measure the oxygen content of a sample that is susceptible to oxidation by a strong chemical oxidant.  The procedure used is the Dichromate Reflux Method (Standard Methods 5220D).  Due to the rapid turn around of this test, it is useful in the monitoring and control of a wastewater facility.

Fecal Coliform
The fecal coliform test is a seasonal permit requirement.  The procedure used is the Membrane Filter Technique (Standard Methods 9222D).  Fecal coliform bacteria indicate the possible presence of other pathogenic organisms.

Chloride
Chloride is corrosive and may be harmful to the metallic pipes and structures of a wastewater plant.  Chloride is determined using the Argentometric method (Standard Methods 4500-Cl B).

Cyanide
Cyanide is used in a number of industries and is extremely toxic to humans. GBMSD analyzes total cyanide using a mini-distillation/colorimetric method (Standard Methods 4500 CN E). 

Residual Chlorine
Residual chlorine is a seasonal permit requirement from May 1 until September 30.  The procedure used is the DPD method (Standard Methods 4500-Cl-G).