New Zealand moss keeps Eppley pool clean
On the first day of each month, Campus Recreation Services pool operations manager Matthew Quigley removes a section of tile floor at the Eppley Recreation Center Natatorium and hauls a yellow cage out of the dark water below.
It’s time to open the cage and replace the seven or eight bags that have rested in the instructional pool’s surge tank for the past month. The mesh sacks hold sodden clumps of sphagnum moss, imported from New Zealand, which help pool staff keep the water clean using less chlorine.
“We had some patrons that said it’s less harsh on their skin, on their hair,” Quigley said. Staff started using the moss in 2011, before the university’s July 2012 decision to cut eight sports programs, including two that practiced in the ERC pool, Quigley said.
“We had the swim team, which spent five to six hours a day in the pool — they really liked it,” he said. We also had water polo. … They said they could breathe easier.”
CRS received a grant for more than $64,000 for the 2010-11 academic year from the University Sustainability Fund so it could set up the moss filtration system. The moss costs about $40,000 per year and reduces spending on chemicals by about $38,000 — a good investment, Quigley said.
“We’re always looking to try and turn something into a sustainable effort,” he said.
Each pool has its own surge tank, which holds water that is displaced when more swimmers climb in. A pump keeps water flowing through the tank, allowing the moss to filter the water.
Sphagnum moss releases pH buffers that make water more resistant to changes in acidity. This makes it easier to keep a pool’s pH between 7.2 and 7.4, the range in which chlorine is most effective as a sanitizer, said Gina Chavez, operations vice president at Creative Water Solutions, the Minnesota-based company that supplies the moss for the Eppley pools.
The moss’s brown leaves carry a negative charge that attracts cations such as calcium and magnesium, pulling the metals out of the water. Chavez said the moss also stops biological contaminants from building up on pool filters.
Creative Water Solutions sends the university a year’s worth of moss at a time. The 1.2 million-gallon competition pool requires 47 bags of moss, and the outdoor recreational pool takes 14. Overall, staff use about 84 bags at a time.
Halfway through the month, the pool staff removes the moss to fluff it, mixing the chlorine-bleached outer layer of each clump with fresher leaves from the inside.
“It’s cool because it’s innovative, but at the same time, I don’t know, I was expecting something bigger. … It just looks like such an unassuming thing,” said Kathy Haines, a public policy graduate student who saw the moss during a sustainability tour earlier this month.
Quigley said the university might be able to recycle used-up moss in the future — for instance, as a moisture-holding blanket to help grass grow. She said she hopes Creative Water Solutions will be able to grow the moss in the U.S. to eliminate the environmental impact of shipping it across the ocean.
“There’s some cost to transport from New Zealand, but I think it’s better to dare and be bold and try new things than to just say, ‘Oh, you know, we spent so much carbon to get here.’ … They’ll keep refining the idea until it does make good economic and environmental sense,” she said.