Officials from several state agencies today briefed the media on so-called "blue-green algae" outbreaks, which they said were likely worse last summer than they have ever been.
But they said they couldn't predict how serious the problem might be this year.
"I don't think any of us really know," said Mike Tate, director of the Bureau of Water at the Kansas Department of Health and Environment. "It seems like a crapshoot as to where we might go this summer."
Blue-green algae are actually various types of cyanobacteria. Under certain conditions, algae blooms can form and become health hazards. Skin contact can cause allergic reactions and ingesting the infected water can cause diarrhea, vomiting and worse. Pets and livestock can die from drinking too much infected water.
Last year, blue-green algae outbreaks in public lakes killed at least five dogs and sickened at least 13 people. KDHE issued warnings at 16 lakes — three lasting most of the summer — and advisories at another four.
Lawrence and Johnson County also temporarily suspended use of Kansas River water last year due to concern that toxic cyanobacteria would move from the river into the municipal water intakes that feed some of the water treatment plants that produce drinking water.
Tate said the conditions that led to the large-scale hazardous algae blooms experienced last year were:
• Spring storms causing significant runoff into lakes;
• Long periods of hot, dry summer weather with little wind;
• Minimal water releases from the lake;
• And accumulation of pollutants in the water, primarily excess nitrogen and phosphorus commonly found in farm and lawn fertilizers.
The source of pollutants in the water varies from lake to lake, Tate said.
"It depends on the particular watershed. There are some, particularly urban lakes, where it may well be urban fertilizer from lawns that are the primary source of the nutrients. Whereas more rural reservoirs, it may be more agricultural related," he said.
Last year was the second year that KDHE issued advisories and warnings for harmful algae blooms.
Advisories mean that activities such as boating and fishing may be safe, but direct water contact should be avoided by humans and entirely by pets or livestock. Warnings mean that all water activity should be avoided, except boating where water is unlikely to splash on passengers.
Six lakes were under warning and advisory for 27 days or more in 2011. At the top end were Logan State Fishing Lake at 111 days, and Marion and Milford lakes at 91 days.
About 6 million visits were made to state parks last year, down nearly 1 million from the year before, said Steve Adams of the Kansas Department of Wildlife, Parks and Tourism.
"Some of that could be because of the excessive heat last summer, too — it's hard to say," Adams said.
He said park revenue fell 9 percent last year to $5.5 million. To offset the loss, the budget bill now being negotiated contains a $800,000 supplemental appropriation for the parks division.
→ More information on khi.org — including symptoms of cyanobacteria infection and how to get water from your private pond tested.