The U.S. Environmental Protection Agency’s (EPA) Water Infrastructure Resiliency and Finance Center, in collaboration with the ...
WWTF improves visibility & reduces energy consumption with LED lighting
Upgrading to energy-efficient lighting has become one of the simplest and most cost-effective solutions for water and wastewater treatment facilities to reduce operational costs and enhance safety and security. As more organizations also look to reduce their environmental impact, high-efficiency lighting also can significantly reduce the carbon footprint of facility operations to meet sustainability goals and mandates.
Recent advances in light-emitting diode (LED) lighting technology have made this efficient, low-maintenance option a good fit for both retrofit and new install applications. In fact, LEDs offer numerous advantages over conventional lighting technology like high-pressure sodium (HPS) and mercury vapor (MV) fixtures:
With the significant savings in energy and maintenance, an upgrade to LED lighting can actually pay for itself, providing a return on investment in, or payback period of, as little as one year in some cases.
Santa Cruz Savings
The City of Santa Cruz (Calif.) Wastewater Treatment Facility (WWTF) processes an average daily flow of 10 million gal per day (mgd), providing regional wastewater treatment and disposal for both the city and the Santa Cruz County Sanitation District, which includes the communities of Live Oak, Capitola, Soquel and Aptos. In operation since 1928, the facility has undergone numerous expansion projects to accommodate growth in the region and now boasts a rated design capacity of 17 mgd.
Aiming to achieve better visibility and reduce energy consumption, the facility recently modernized its exterior area and site lighting, upgrading from HPS and MV fixtures to new Dialight DuroSite LED fixtures in several areas.
Money & Time
With hundreds of fixtures to light its exterior structures 12 hours a day, seven days a week, the Santa Cruz treatment facility previously used a combination of HPS units ranging from 70 to 400 W and MV fixtures in 175 to 400 W models. For safety and security purposes, the entire facility is under 24/7 closed-circuit television surveillance—yet the poor quality of light emitted by the antiquated fixtures hindered visibility and reduced the image clarity of the closed-circuit system.
In addition, the HPS and MV fixtures required constant maintenance to change bulbs and ballasts, costing the plant both money and valuable personnel time. Not to mention, the cost of hazardous material disposal for the bulbs added to the ongoing maintenance expense and the environmental impact.
As part of a citywide Climate Action Program to reduce energy consumption and to resolve its lighting challenges, the facility experimented with several LED lighting solutions, including one from Dialight. Impressed with the way the Dialight fixture outperformed the others, the facility ultimately chose Dialight to replace 82 fixtures in its solids dewatering building, pre-aeration and trickling filters with the company ’s DuroSite LED fixtures, including 33 Low Bays specially designed for areas of low clearance, and 49 High Bays—19 with 14,000 lumen output and 30 with 12,000 lumen output.
The entire changeout took just five days—about 30 to 60 minutes per fixture. The 12/7 lighting was outfitted with a combination of photocells and timers, taking advantage of the Dialight LED’s instant-on capabilities.
LED fixtures typically draw less than half the wattage of HPS and MV (on average). With the new fixtures, the Santa Cruz facility reduced its lighting energy usage and cost by more than 50%, significantly lowered its CO2 emissions and realized a dramatic improvement in visibility, contributing to more robust security throughout the facility.
With each fixture expected to last up to 10 years, the retrofit has reduced lighting maintenance and costs for the next decade. A rebate also was approved through a local incentive program based on energy savings, and the entire project will pay for itself within three years.