Aqua Engineers is a local Hawaiian company founded almost 40 years ago which delivers operations, engineering and construction management to the water and wastewater industry throughout Hawaii. Also, as an owner and operator, Aqua Engineers is keenly focused on the return on investment for process equipment decisions, but also on the safety of its operators and surrounding community. Choices between disinfection technologies on the Hawaiian Islands involves evaluating a host of trade-offs that often includes a heavy weighting of reliability, self-sufficiency and resilience as a result of the inherent distance from mainland suppliers. In evaluating disinfection options for various projects, Aqua Engineers came to following conclusions:
Based on this analysis, Aqua Engineers evaluated two wastewater treatment plants that both generated water for beneficial re-use for conversion to the latest version of on-site hypochlorite generation. Both the Puhi Sewer & Water WWTP (0.4 MGD) and the Turtle Bay WWTP (0.2 MGD) had already converted from gas chlorine to bulk hypochlorite (~ 12.5% sodium hypochlorite) in previous years. OSHG uses power, salt and softened water to produce a ~ 0.8% concentration (8,000 ppm) of sodium hypochlorite as a powerful water disinfectant.