By E.B. FURGURSON III, Staff Writer

The Capital

Published 06/11/09

The South River Federation's annual "snapshot" revealed the watershed in fair shape in the three-hour window volunteers took to measure conditions around the river and its tributaries in April. But looks are sometimes deceiving.

Like last year's snapshot, the results underscored the connection between rainfall and water quality.

It had not rained for days previous to the April 25 effort, in which 35 volunteers fanned out around the watershed to test 40 sites from Crownsville to Thomas Point.

Because there was no rain flushing nutrients and bacteria into the river and its roughly 300 miles of tributaries, readings for those and other elements mostly fell in the good range.

"One volunteer told me after participating, 'Finally I realized the connection, the river's connection to human health,' " South Riverkeeper Diana Muller told about 60 federation members at the organization's general meeting Tuesday evening.

The testing showed all the major parameters tested were near normal levels, including pH, bacteria, water clarity and nutrients.

In 2007 after a rainfall, bacteria laden runoff spiked readings across the watershed, over half the sites failed the EPA standard for bacteria; meaning there were more than 104 bacteria colonies per 100 milliliters of water.

This year only two did. And in 2008, 23 percent of the sites, with light precipitation falling a few days ahead of time, ran afoul of EPA guidelines.

This year most of the parameters showed better conditions.

''But there are still important bits of information out there that indicate a disturbing impact on water quality," South River Federation Executive Director Erik Michelsen said.

Water clarity readings were pretty good. The state sets a clarity reading of 50 as a threshold, and all but one site came well below that mark, most in the teens.

PH readings were in the normal range as well.

Dissolved oxygen readings, which indicate the amount of oxygen in the water to support aquatic life, were a low spot in the snapshot, with many sites still below the 5 parts per liter threshold to support life. Most readings were 4 parts or lower.

Phosphorus levels, normally associated with sediment runoff, were also high. And the federation is taking a closer look at historic numbers related to that compound. "One thing that stands out is the high phosphorus, many readings were above the threshold, while bacteria and other readings were lower," Michelsen said. "We are looking at the role phosphorus is playing in algal blooms."

That is not all the federation is doing. Through Operation Clearwater, volunteers from several river organizations are testing bacteria levels at swimming beaches throughout the area.

Riverkeeper Muller is testing water quality once a week at 19 sites with an instrument that measures five parameters. And the organization's "riverwatchers" test year round for similar indicators.

"Some are even cutting holes in the ice to get the job done," Muller said.

That underscored the point made by Michelsen at the outset of the meeting, which also had on display a series of water quality projects done by the county's first class of Master Watershed Stewards.

"None of what we do would be possible without the active engagement of all our volunteers," he said.