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Some people may not realize that the sanitary sewer and the storm sewer are two different sewer systems. The sanitary sewer is a network of underground pipes that attach each home and business in the collection area to the wastewater treatment plant. The storm sewer system is a network of underground pipe that collects rainwater runoff and channels it directly to streams and rivers without treatment. In the case of the sanitary sewer it is sealed as best it can be from receiving rainwater runoff which is detrimental to the wastewater treatement process. This collection system must be routinely inspected and maintained in order to ensure correct transfer and treatment of all residential and commercial wastewater placed into it.
Extended Aeration (EA) Wastewater Treatment System
EA treatment plants are based on time-proven process designs carefully engineered to optimize performance. EA plants are one of the most basic and versatile sewage treatment technologies available.
An EA plant consists of two major compartments, the main aeration chamber and a clarifier or settling tank. After initial screening, the waste water (sludge) enters the main aeration tank which holds sludge for 24 hours. Here, air is introduced and natural bacteria feed on the organic portion of the sludge reducing BOD concentrations. The partially treated sewage then flows to the final settling tank for clarification, clear water is discharged after being filtered and disinfected. Heavy solids are left behind. These heavy solids are then discharged into tanker trucks and transported to a facility permitted to further treat the condensed sludge.
Solids extracted from waste water have to go somewhere right? Halifax Area's sludge is clarified (settled) into a thick slurry then transported by tanker truck to a sludge disposal facility. What is left behind is clean water which is discharged back into the water table. A secondary process sends sludge onto sand drying beds where liquid drains out of the sludge mixture and back into the treatment system, leaving behind a dried mixture similar to potting soil that can be raked off and disposed of to permitted dumping sites or garbage disposal service.
2018 Chapter 94 Report