|
Water drainage systems are actually more complex than some people might think. When people imagine elaborate drainage systems underneath a city, they envision absurdly spacious sewers that are the stuff of pulp fiction. Sewer pipes are almost never that spacious; the really large ones (cisterns) have been built long ago. Nowadays, drainage systems are composed of narrow pipes with accessories that aid sanitation. There are “storm drains” that lead the storm water into the drainage system underground, where it undergoes sanitation procedures before being discharged into the open water. After being drawn into the storm drain (the grilled opening located along canals), the water and its contaminants are led out through a series of pipes. This wastewater almost always includes blackwater, which is wastewater with fecal matter and urine. This is breeding ground for toxins and bacteria extremely harmful for marine life. Luckily, there are now drainage systems equipped with accessories that keep sewage from entering the open water and poisoning marine life. Before entering the pipe leading to the open water, large debris like fallen leaves, twigs, and candy packs get caught in storm drain filters. Some debris get through, but before the wastewater is released into the sea, these encounter the snout. This is a curved plate that keeps floating debris from entering the pipe. The snout is sometimes paired with a bio-skirt, which is a “skirt” of cloth strips. Together, these stormwater bmps further rid the remaining water of waste. Smaller debris, microorganisms and oil get caught in the cloth. The snout is sometimes also installed with a trash screen, which filters bigger debris that might have gotten through the storm drain. The area the wastewater flows through before passing the exit pipe may also have other stormwater best management practices or stormwater bmps like use of the flow restrictor and the odor control filter. The flow deflector is a stainless steel flap attached to the pipe walls. The deflector plate manipulates the water flow to keep floating debris from flowing into the pipe. There may also be an odor control filter attached to the snout; this needs to be replaced regularly.
Related Articles -
storm drain filters, stormwater bmps,
| 
