Milwaukee Brews Drug Free Tap Water: With Ozone
We mentioned earlier this week that trace amounts of prescription drug residues in some drinking water supplies are no reason to go for the bottled water, and that off-the-shelf technologies are capable of removing most unwanted drug residues from municipal effluents and tap water, respectively. Milwaukee, Wisconsin makes a good case study.
Pain relievers, antibiotics and other prescription drugs, caffeine and a chemical created inside the bodies of smokers are among the chemicals found in recent tests of Milwaukee's sewage and water from the city's harbor and Lake Michigan.
Lake Michigan is Milwaukee's drinking water supply. Its sewerage effluent ends up not far from the water intake. Good incentive for keeping performance up, unlike in other communities which discharge effluents into a river, making it some downstream city's problem.
On a related note, it was in March and April of 1993 that Milwaukee suffered a serious outbreak of waterborne cryptosporidium infections, after which City officials seem to have turned to the use of ozone for water treatment. They had good reason to spend the extra money. According to CDC researchers:
The total cost of outbreak-associated illness was $96.2 million: $31.7 million in medical costs and $64.6 million in productivity losses. The average total costs for persons with mild, moderate, and severe illness were $116, $475, and $7,808, respectively. The potentially high cost of waterborne disease outbreaks should be considered in economic decisions regarding the safety of public drinking water supplies.Back now to our story about drug residue removal in Milwaukee water.
Chemicals in the water are destroyed by ozone mixed with the lake water at the beginning of the drinking water treatment process, and consumers are not exposed to them, said Water Works Superintendent Carrie Lewis. There were two exceptions last year, and only one of the compounds is a pharmaceutical.Anyway, we digress. Here are the two take-home messages.
Tests of treated drinking water in the plants found 2 parts per trillion of cotinine and 0.5 parts per trillion of lincomysin, an antibiotic. Lincomysin was not detected in lake water coming into the two treatment plants, however, Lewis said.
Neither chemical was found in separate tests of water flowing through pipes to homes and businesses in the regional distribution system.
"Milwaukee tap water is clear of pharmaceuticals," Lewis said.
In the Milwaukee example, the advanced potable water treatment was implemented as a disease preventive measure that also happens, gratefully, to eliminate the drug residues. Ozone added to water forms a hydroxyl ion that is such a powerful oxidant it breaks down odor and color causing organic materials as well as pharmaceuticals. At Milwaukee, ozone is added to raw water before the final polishing steps. Consumers are not drinking ozone bubbles.
A similar approach can be used in place of chlorine for sterliziing wastewater treatment plant effluents, lowering the exposure of drug residues to fish and aquatic life.
In other words, the treatment technology is there. Voluntary improvements often come first where hard lessons are learned (as in Milwaukee). But, we should not need illness to learn that fecal pathogens and drug residues in the free environment can be dangerous. Political will, and a philosophy which admits that government can bring positive change, are all that is lacking for other US cities to tackle this problem.
Hats off to Milwaukee for going beyond the technology solution. The community is implementing an unused drug collection program to avoid drug residues getting into Lake Michigan in the first place. See the link below for details.
Reminder:: The USA has a Clean Water Act which was set up specifically to handle precisely the sort of problems outlined in this post. No new laws really are needed. Just enforcement, an updating of technology standards, perhaps, and budget appropriations at the Federal and state levels. A watershed based approached would make the most sense.
Via::Journal-Sentinal Online, "Drug disposal advocated for lake's sake" AND Milwaukee Water Works AND CDC, Cost of Illness in the 1993 Waterborne Cryptosporidium Outbreak, Milwaukee, Wisconsin Image credit::Google satellite map of Milwaukee lakefront area, mouth of Milwaukee River.