BRATTLEBORO -- When it comes to E. coli levels in area waterways, there's good news and there's bad news.
First, the good: Officials say their second round of testing this season showed generally declining numbers of the potentially harmful bacteria.
However, a majority of testing sites still host E. coli in numbers that are above acceptable standards for safe swimming. And two sites -- both on the Williams River -- generated bacteria levels that were too high to be accurately measured.
"Both of the sites have had elevated E. coli results in the past, and follow-up will need to occur to understand the possible cause(s)," wrote Laurie Callahan of Southeastern Vermont Watershed Alliance.
As was the case with the volunteer organization's first report from the June 13 testing, the latest results may have been affected by significant rainfall prior to sample collection on June 27.
"One of our volunteers in Rockingham recorded 1.5 inches of rain on Monday, June 25," Callahan wrote in a memo accompanying the alliance's statistical report.
Rain can wash E. coli into streams from nearby terrain, causing temporarily elevated bacteria levels.
Other than that possibility, though, it remains unclear where excess E. coli may be coming from. Officials have said farm runoff is a common source, as are leaky septic systems.
Regardless of the source, elevated levels of the bacteria -- which is found in fecal matter --
That's why state and federal officials set "suitable for swimming" E. coli levels at a maximum of 235 organisms per 100 milliliters of water.
In the alliance's June 13 report, 11 of the 17 tested sites exceeded that standard. In the June 27 report, 11 of 19 tested sites -- a slightly lower percentage -- were higher than governmental standards.
Once again, the Williams River was a trouble spot. Four of five testing sites on that waterway were above acceptable levels.
The Rainbow Rock swimming hole in Chester came in at 329 organisms per 100 milliliters, while a spot near Missing Link Bridge in Chester showed two results that exceeded standards -- 249 and 299.
However, that actually represented a big improvement for the Missing Link: The June 13 test showed an E. coli level of 1,987 there.
Two sites on the Williams River fared far worse. A testing spot below Chester's wastewater-treatment facility and another at Bartonsville Bridge in Rockingham each had E. coli greater than 2,420 per 100 milliliters, which Callahan explained as an undetermined number that "exceeded the upper limit of the test method used."
Those were, by far, the worst numbers in the June 27 survey. But several other sites had higher-than-suitable E. coli statistics:
* Middle Branch of the Williams River in Chester (518). There were no results in the June 13 report for this site.
* Saxtons River: At Bellows Falls/Westminster "sandy beach" (239); below the wastewater treatment facility (262); and at Stickney's field swimming hole (249).
* West River: At Rowes Road in South Londonderry (345); above the Route 100 bridge in South Londonderry (299); and below Mountain Marketplace in Londonderry (two results, 273 and 249).
Overall, though, E. coli counts were down from the previous test. Each of those three West River sites showed significant improvement: For example, both South Londonderry sites had registered E. coli levels of 921 on June 13.
Other significant findings of the alliance's June 27 report:
* Two sites that had exceeded governmental E. coli standards fell back into compliance: Whetstone Brook at Dettman Drive in West Brattleboro dropped from 345 to 65, while Rock River at Indian Love Call above the Route 30 bridge declined from 308 to 82.
* Five West River sites scored well: Tests showed samples taken at Milk House Meadows, Brattleboro Professional Center, Dummerston Covered Bridge, Brookline Bridge and Ellen Ware Road swim hole had E. coli levels ranging from a low of 55 to a high of 96.
* There was no available June 27 data for Whetstone Brook near Brattleboro Food Co-op, which had been one of the worst E. coli sites in the June 13 test.
The alliance's next tests are scheduled for July 11. A complete report and more information is available at the organization's website: https://sites.google.com/site/vtsevwa.
Mike Faher can be reached at email@example.com or 802-254-2311, ext. 275.