Ala Wai Canal Sewage Issue
Elisa R. Lewis
SCI/256 People, Science, and the Environment
April 10, 2013
Ala Wai Canal Sewage Issue
Untreated raw sewage released into the Ala Wai Canal can cause direct and indirect oxygen depletion, algae blooms, and disease-causing pathogenic bacteria and viruses. Human waste contains a high concentration of nitrogen and phosphorus. Phosphorus causes increased algae in freshwater and nitrogen causes increased algae in marine waters. When these nutrients are introduced to an aquatic system is causes rapid growth of algae which depletes the oxygen in the water that the invertebrates and fish need to live. In addition, species that ...view middle of the document...
Because the flow of the canal empties into the nearby shore marine water, Waikiki waters and adjacent beaches will be affected from the runoff. The lack of a backup line is forcing this decision while the broken pipe is repaired. This redirection will prevent waste from backing up into homes, hotels, and businesses located in the Waikiki area which would eventually end up in the canal anyway (The Free Library, 2007).
Once they redirect the waste, water samples will be taken to determine contamination levels and when the water will be safe again. Samples will be taken from canal stations, shorelines, and surf sites. Signs will be posted to alert the public of the contamination. Beaches should only be closed for 7-10 days and the water should be back to a safe level in 3-4 days. The additional closure days will be used to test sand and other surrounding agricultures. This is the best option as it is less damaging than having sewage back up into homes, hotels, and business. When buildings are contaminated with sewage penetration of the sewage into wood, concrete, and porous surfaces can lead to the growth of potentially disease causing microorganisms that can be toxic to humans. Additionally, the bacteria can linger for some time after the event with occupants unknowingly being exposed to the dangers. One solution to prevent another such disaster is to construct wetlands to capture and treat storm water.
Currently the Ala Wai Canal is on the Environmental Protection Agency (EPA) list of impaired streams. The canal currently receives storm water from the surrounding areas of Manoa and Palolo Valleys, including the University of Hawaii, Manoa campus. The wetlands will be used to capture and treat storm waters and reduce pollutants, nitrogen, phosphorus, heavy metals, and pathogens contained in the raw sewage. The EPA recommends wetlands as a viable option for treating runoff. Especially in areas where there is a high concentration of runoff and a desire to protect ecosystems. The removal of the pollutants makes the water reusable for irrigation purposes. The benefits to this is it reduces the...