SHEBOYGAN LAUNCHES THE LARGEST DRINKING WATER UV DISINFECTION SYSTEM IN THE STATE
In 1887, a private company began pumping untreated Lake Michigan water to citizens of Sheboygan. The brick building that housed the original steam pump still stands at 72 Park Avenue. Although at that time, pumped water must have seemed a marvel, the lack of treatment resulted in aesthetic problems and the spread of water-borne disease including typhoid.
By 1922, the public Water Utility had been formed, and the Utility began adding chlorine gas to disinfect the water. However, the Lake Michigan water was still not treated in any other way, and water quality varied from day to day. In 1929, the Utility began construction of a complete water treatment plant, using pre-treatment and filtration processes to clarify the water.
During the intervening years, many changes occurred as the City grew and increased its thirst. Many changes took place in the water industry as well, more recently including the advent of secondary disinfection barriers. These secondary barriers help protect against system failures by ensuring that water disinfection does not rely on one process. The most common barriers include ozone gas, membrane filtration, and ultraviolet disinfection.
On August 1, 2016, the Sheboygan Water Utility began operation of its Ultraviolet Disinfection Facility (UVD). Ultraviolet, meaning beyond violet, is high-energy light that is invisible to the human eye. UV disinfection inactivates harmful microorganisms including E.coli, cryptosporidium and giardia. This technology works in conjunction with existing treatment processes to provide an additional disinfection barrier before water leaves the water treatment plant. The Utility determined that UV was the most cost effective secondary barrier.
The Sun is the biggest source of ultraviolet light in everyday life. On a sunny day at the beach, UV can pack a powerful punch. When passed through water, UV light imparts energy to the genetic material (DNA) within bacteria, viruses and protozoa, eliminating their ability to reproduce and cause infection. Unable to multiply, the microorganisms no longer pose a health risk.
UV does not add any new chemicals to the treatment process. Chlorine is still present as the primary disinfectant and to provide disinfection throughout the water distribution system.
The Water Utility’s UV system was funded by a Safe Drinking Water loan from WI DNR. Typical monthly electrical costs to run the system are about $900. Construction began in 2015 and continued through much of 2016. Due to limited space available, the UV system was squeezed into very tight quarters in a location where critical water pipelines had to be re-located.
Utility staff worked hard to incorporate the new process and to complete all necessary tests with some of the UV equipment. With time and patience, staff worked through all of the issues and feel extremely confident with the new system. So now, with its own UV system, the sun never stops shining at the Sheboygan Water Utility.