State of the Upper Merrimack 1995-1997,
a river quality report
Stephen C. Landry and Michele L. Tremblay, principal authors
The Upper Merrimack Monitoring Program (UMMP) monitors river quality from the Upper Merrimack (Franklin to Bow), Pemigewasset, Winnipesaukee, and Contoocook Rivers through E. coli bacteria, field chemistry, and benthic macroinvertebrates analysis. The volunteer-staffed program began in 1995, when a cooperative agreement was signed by the Upper Merrimack River Local Advisory Committee (known locally by its acronym, UMRLAC), Merrimack River Watershed Council, and the NH Department of Environmental Services. At that time, the UMMP sampled seven sites. In 1996, the program was expanded to include a total of eleven sites. Many partnerships, including Franklin Waste Water Treatment Facility, Franklin High School, River Watch Network, and Saint Paul’s School (see appendix for full list), have contributed to the success of the UMMP. The UMMP has also hosted guests including Governor Jeanne Shaheen, who donned waders on Earth Day and learned about biomonitoring with her daughter, Molly.
In 1996, the UMMP received the first of two grants from the New England Interstate Water Pollution Control Commission. These grants allowed UMMP sustainability and independence by funding the purchase of equipment and support materials. The second grant provided support to expand the UMMP’s strong educational component. In addition to grants, support has been provided by municipalities and through innovative programs such as “Adopt-a-River Site.” This program works with corporations and groups who support the program by sponsoring a monitoring site. Sponsors provide financial support as well as volunteer time and receive free training in a number of river monitoring techniques.
The UMMP generated the data in this report by adhering to its US Environmental Protection Agency-approved Quality Assurance/Quality Control Plan. Although one of the goals of the UMMP to generate credible water quality data, a significant component of its work has focuses on watershed education efforts. This document is intended not only to present data and the validity of volunteer work, but also as an educational tool. The Upper Merrimack Monitoring Program volunteers have presented at conferences and other events throughout the northeast and at national conferences, conducted workshops, and provided assistance to other watershed groups.
Hundreds of volunteers (see appendix for full list) from all over the region have spent countless hours participating in the UMMP. River conservationists, municipal officials, anglers, teachers, students, and many others have assisted the UMMP by collecting water samples and benthic macroinvertebrate specimens, analyzing macroinvertebrates, and performing other field tasks. Their willingness to learn about watershed science and spend their free time is at the core of the UMMP’s success—making it one of the most ambitious volunteer water quality monitoring programs in the country. The Upper Merrimack Monitoring Program has been featured numerous times in the press and is proud of the accomplishments of this completely volunteer-staffed and managed monitoring program.
When asked at a recent conference to summarize the state of the Upper Merrimack River watershed in the form of a newspaper headline, the Upper Merrimack Monitoring Program responded, “When it rains, it’s poor!” Three years of E. coli sampling on the Upper Merrimack River by UMMP volunteers has been plotted against flow data to illustrate the impacts of nonpoint source pollution (or polluted runoff) on river quality during high flow events in the Upper Merrimack River watershed. Elevated concentrations of E. coli bacteria associated with rain events and/or high flow events were recorded during each of the three study years. During one high flow event in 1995, E. coli concentration at six out of seven sites monitored exceeded the Class B Surface Water Quality Standard for New Hampshire. This demonstrates that the Upper Merrimack River is constantly at risk from the threat of nonpoint source pollutants such as fertilizers and poorly-maintained septic systems.
Contrary to the E. coli monitoring data that provides the UMMP with an immediate or “snapshot” assessment of river quality when comparing to state surface water quality standards, the collection and analyses of benthic macroinvertebrate community data provides a long term diagnosis of river health. Although three years of biological community data are too sparse for discerning long-term river quality trends, the data collected since 1995 provides enough information to allow for biological community assessments at each site from which river quality can be inferred. One distinctive trend or transition in community composition is evident when biological data from 1995 to 1997 is analyzed from site to site from confluence to Garvins Falls in Bow at the terminus of the Upper Merrimack. There are parallel declines in the number of sensitive macroinvertebrate species (EPT Richness) and habitat assessment scores that mirror the flow of the river from Franklin down to Bow. A corresponding decline in overall river assessment scores results from this gradual decline in biological community health and diminished habitat. It is important to note however, that seven out of the ten sites that had biological community assessments performed, contained high percentages (at least >50%) of EPT taxa within the macroinvertebrate community. This indicates that river quality at these sites is considered to be “non-impaired” or “excellent” which directly corresponds with the overall river quality ratings (assigned by the UMMP) that ranged from “good” to “excellent.” Sites 9, 10, and 11 failed to produce a macroinvertebrate population that had a significant percentage of EPT organisms and subsequently received the lowest range of overall river assessment ratings from “poor” to “fair.”
Although there is a definite decline in community diversity and taxa richness associated with the UMMP sites located in the lower reaches of the Upper Merrimack River, it is important to note that EPT taxa have been collected at all eleven sites since 1995. This indicates that although the habitat may not be ideal and that certain field chemistry parameters may be somewhat limiting, representatives from sensitive taxa are present and indicate the absence of concentrated sources of pollution. Field chemistry parameters collected over the three-year period support this statement and reflect results that fall well within the acceptable ranges established for New Hampshire surface waters.
The UMMP will continue to collect E. coli, field chemistry, and macroinvertebrate samples to establish a baseline biological “standard” for the Upper Merrimack as well as for the purpose of distinguishing long-term river quality trends. In summary, water quality in the Upper Merrimack is generally good—but a significant threat exists from nonpoint source pollution. It is imperative that Best Management Practices be implemented for commercial and industrial properties, municipal storm water, agricultural operations, and residential areas. The Upper Merrimack is the primary artery that courses through the hearts of our communities. We all have the responsibility to keep it clean and healthy for this and future generations.