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New Technologies:  New Processes for a Better Environment


Ultraviolet Disinfection

Ultraviolet (UV) disinfection uses radiation to penetrate microorganism cell walls to either prevent reproduction or destroy the viability of bactaria and viruses. Short exposure times, usually seconds, are sufficient to inactivate micorogamisms. It is used in many common food and drink processes.

Drinking water supplies and high purity systems in laboratories, pharmaceutical companies and hospitals are often UV disinfected. Fish farms and hatcheries use UV to disinfect the feed water.

Food and drink manufacturers use it to reduce the risk of contamination in their processes. UV disinfection is now being used at several of the City's wastewater facilities. The Kailua and the Wahiawa treatment plants use UV to disinfect secondary treated wastewater before discharging effluent. At Honouliuli, secondary effluent is UV disinfected by the Board of Water Supply's Ewa Reclamation Facility as part of recyclingwater for irrigation and industrial uses.

A UV unit at Sand Island WWTP disinfects primary treated wastewater effluent before discharging it through a deep ocean outfall.



Organic Fertilizer pellets

The City and County of Honolulu has contracted with Synagro to design, build and operate a municipal biosolids facility near the Sand Island treatment plant.

The public/private partnership facility was operational in 2006 and processes up to 10,000 dry tons of biosolids annually. Waste that was landfilled is now turned into a commercial exceptional grade Class A organic fertilizer product, marketed by Synagro.

The nutrient-rich pellets are safe for general gardening and landscape use. Local retailers, landscapers and golf courses as well as large-end commercial growers use this product. Honolulu joins many cities that have turned to pelletization programs due to landfill and environmental constraints, among them Boston, Tampa, Houston, New York City and Sacramento.

Last Reviewed: Friday, February 03, 2012