Harmful algae blooms (HAB) have traditionally been considered a "saltwater" phenomenon. Most general media attention has focused on outbreaks in areas like the Gulf of Mexico and Chesapeake Bay.

But as water managers around the Great Lakes have long known, and this updated law acknowledges, nutrient pollution is a major environmental problem in all 50 states.

The numbers below show how even a temporary disruption in drinking water service impacts a community's economy.

1 microgram per liter: That's the level of microcystin determined to be safe by the World Health Organization. Microcystin is released from algae that feed off of phosphorus and other chemicals often associated with farm and fertilizer run-off.

2.5: The number of parts per million of microcystin found in the Lake Erie water samples that spurred Toledo's ban, according to Dr. David Grossman, director of the Toledo-Lucas County Health Department, as reported in The Toledo Blade.

50,000: Toledo's Division of Water Treatment conducts more than 50,000 tests annually. Samples are collected from the raw water source, through the production and treatment process, distribution network, and from consumer taps.

441,815: The population of Lucas County, Ohio, according to the 2010 census. Local news reports indicated approximately 440,000 people were impacted by the ban.

3: The number of labs used to confirm the city's water was once again safe, as indicated in several reports.

$1 million: The amount of money Toledo spent last summer on chemicals to protect the city's water supply from Lake Erie's algae, according to The Toledo Blade.

48: The approximate number of hours the ban lasted. Toledo Mayor D. Michael Collins celebrated the moment by drinking a glass of the tap water.

20: The approximate percentage of the world's supply of surface fresh water contained in the Great Lakes, according to EPA.