MISSOULA, Mont. -

The Montana Department of Environmental Quality approved on Friday a new set of water quality standards aimed at reducing the amount of nutrients that fuel algae growth.

Large concentrations can suck nutrients from the water, and when algae decomposes it depletes the oxygen too.

DEQ Planning Manager George Mathieus helped develop the standards, and he says they’ll be implemented in phases over the next 20 years.

The standards establish limits on the quantity of phosphorus and nitrogen -- common in fertilizer and human waste -- from entering waterways through what Mathieus calls “point sources.”

"If you think of a point source, it's as simple as a pipe going into a stream,” said Mathieus. “Municipalities, wastewater treatment plants."

He says the standards also apply to “nonpoint sources” like agriculture runoff.

The quantity limits deal in parts per million, and they're ambitious, aiming to reduce nutrient levels in some cases by 1,000 percent in 20 years.

"A lot of this is banking on that technology getting better, and it will become more cost effective...The important thing is the standards that were adopted and the permit limits that were adopted on Friday will result in immediate improvements to a lot of the streams in the state."

Before they take effect, the federal Department of Environmental Quality has to approve the standards, which can take up to two months.

For a closer look at the standards and who they will affect, click here.