TOLEDO, Ohio (AP) — The U.S. Environmental Protection Agency plans to come out with new guidelines that will give cities and water treatment plants a blueprint for dealing with the type of algae-borne toxin that contaminated the drinking water in Ohio's fourth-largest city, a federal official said Wednesday.

A new health advisory is on target to be finalized sometime next spring, said Peter Grevatt, director of the agency's groundwater and drinking water office.

The advisory will include guidelines on what is a safe level of microcystin in drinking water and how to treat it, Grevatt told members of a congressional subcommittee in Washington.

The toxin that's produced by algae found in fresh water can cause headaches or vomiting when swallowed and can be fatal to dogs and livestock.

The EPA began working on the new guidelines well before toxins from algae in Lake Erie fouled the water supply for more than 400,000 people in Toledo and southeastern Michigan for two days in August, Grevatt said.

Environmental regulators from Ohio, Indiana and Michigan met with federal officials soon after Toledo's water crisis to press the agency for more help in dealing with the toxins.

Only Ohio, Oregon, Minnesota, Florida and Oklahoma have their own drinking water standards for microcystin. Most of those states rely on a measurement suggested by the World Health Organization, which is based on research from two decades ago.

The biggest challenges in coming up with the new guidelines, Grevatt said, are a lack of research and the number of different toxins produced by algae.

Water plant operators across the nation also have been calling for help with dealing with algae-tainted water, including how often to test the water and more sharing of information on combating the toxins.

Algae outbreaks — some that leave behind a variety of toxins and some that don't — are popping up increasingly in every state, fouling rivers and lakes of all sizes.

Members of the U.S. House's Energy and Commerce Subcommittee on Environment and the Economy also spent time asking about efforts to cut down on the nutrients feeding the algae, such as phosphorus from farm fertilizers, livestock manure and sewage overflows. Heavy rainstorms washing pollutants into the water and warm weather help the algae grow, too.

"It's less expensive to control pollution than to clean it up," said Rep. Paul Tonko, a Democrat from New York.

Ohio EPA Director Craig Butler said the state is doing a number of things to reduce phosphorus runoff and improve testing.

John Donahue, president of the American Water Works Association, told the committee that if the water coming into municipal plants isn't clean, residents will end up paying up more for the costs of treating the water.