During the summer of 2009, Merrimack River Watershed Council staff, interns and volunteers measured water quality in the Merrimack River in Massachusetts and southern New Hampshire as part of MRWC’s Merrimack River Water Quality Monitoring, Analyzing, Protecting and Promoting (MAPP) Program. On four separate occasions, two in May and two in August, pH values were found to be considerably lower than normal, and well below the lower limit of 6.5 set by the state for safe swimming, boating and fishing. [For those whose high school chemistry class is a bit fuzzy, pH is a measure of acidity and ranges on a scale of 1 (acidic) to 14 (basic), where 7 is the neutral value for pure water. The Merrimack usually ranges from 6.5 to 6.8.]
On four days in May and August, pH values as low as 3.3 to 4.1 were recorded in various locations from Lowell to West Newbury - meaning the river was as acidic as strong vinegar, and low enough to potentially cause fish kills.
For additional information and details on these findings, please see the full report (PDF).
- Tracie Sales, MRWC Water Resource Manager
