This permit reflects secondary treatment requirements and limitations. It is determined by a simple test that measures oxygen depletion on a series of bottles of buffered distilled water seeded with active bacterial cultures. In addition, different dilutions of the wastewater being tested are added to the bottles. The organic content in the wastewater will cause a depletion of oxygen which is measured after a period of five days. Fish and other aquatic life need dissolved oxygen.
Fish kills can result from a lack of oxygen.
This test is performed by filtering a known volume of the wastewater through a pre-weighed filter paper, drying it to remove the water content and reweighing it to determine the suspended solids content. These solids include both organic and inorganic matter. To determine the organic portion or VSS, you must burn the filtered solids at 550 degrees Centigrade in a muffle furnace and weigh the remaining portion. The purpose of chlorinating the effluent is to kill potentially pathogenic bacteria during the summer months when the receiving waters are most susceptible due to recreational use and assimilative capacity of the waters. Analyses are run three times per day during the chlorination period for remaining fecal coliform.