2001 water quality assessment report

Biology

MDFW regularly stocks salmon fry and trout in Yokum Brook.
In August 2001 MDFW conducted backpack electrofishing in Yokum Brook along Route 8 just below the Bear Creek Store Bridge in Becket (Richards 2003). Six species were collected from within this segment, including, in order of abundance, Atlantic salmon, blacknose dace, brook trout, longnosed dace, creek chubsucker, and a brown trout. Multiple age classes of Atlantic salmon and brook trout were found.
In September 2001 DWM conducted a modified Rapid Bioassessment Protocol III (RBP III) benthic macroinvertebrate survey in three reaches of Yokum Brook in Becket: downstream from Route 8 near intersection with Carter Road (approximately 50m upstream from the Silk Mill Dam) (Station YB01A), 100m upstream from Prentice Place (between the Silk Mill and Ballou dams (Station YB01B) and downstream from Ballou Dam near the Becket Elementary School at the mouth of the brook (Station YB01C, Appendix B). The benthic community at the most upstream station (YB01A) was extremely diverse and was considered to represent the “best attainable” conditions in the watershed. It was, therefore, used as a reference station (Appendix B). Backpack electrofishing by DWM in September 2001 in this reach of the brook resulted in the collection of seven species of fish. These included, in order of abundance, Atlantic salmon, blacknose dace, yellow perch, longnosed dace, eastern brook trout, brown trout, and a creek chubsucker. Multiple age classes of Atlantic salmon, eastern brook trout, and brown trout were found. A small amount of green filamentous algae was observed. However, coverage in this partially canopied reach was very low (<1%) (Appendix D, MA DEP 2001c). The RPB III analysis of the benthic macroinvertebrate community between the Silk Mill and Ballou dams (Station YB01B) indicated non-impacted conditions compared to the upstream reference station on Yokum Brook (Station YB01A). The fish community in this reach was comprised of five species, including, in order of abundance, Atlantic salmon, eastern brook trout, blacknose dace, yellow perch, and a creek chubsucker. Multiple age classes of Atlantic salmon and eastern brook trout were found (Appendix B). The algal coverage was very low (<1%) (Appendix D, MA DEP 2001c). The RPB III analysis indicated that the benthic community at the most downstream station sampled in Yokum Brook (Station YB01C) was non-impacted when compared to upstream reference station on the Yokum Brook (Appendix B). Six species of fish were collected from this location including, in order of abundance, blacknose dace, slimy sculpin, longnosed dace, Atlantic salmon, eastern brook trout, and brown trout. Multiple age classes of Atlantic salmon and eastern brook trout were found (Appendix B). No algae were visible at this sampling location (Appendix D).

Chemistry – Sediment

On 26 July 2001 the USGS conducted a screening examination of sediments behind two dams on Yokum Brook - above the Silk Mill Dam (the upstream dam that has now been removed) and above the Ballou Dam (the lower dam that is still slated for removal) (Zimmerman and Brealt 2003). Three sediment cores were taken from behind the Silk Mill Dam and one sediment core was taken from behind the Ballou Dam. Sediment samples from these cores were analyzed for a suite of organic and inorganic constituents. Polycyclic aromatic hydrocarbons (PAHs) were detected in all samples analyzed, ranging in concentrations from 2.2 to > 5 ppm (the deepest core samples having the highest concentrations). The Lowest Effect Level (L-EL) guideline for total PAH is 4 ppm. However, the Severe Effect Level (S-EL) cannot be calculated (no total organic carbon data are available for the calculation). Two of fourteen samples, both from the Silk Mill Dam, slightly exceeded the L-EL. Three deep core sample results (two behind Silk Mill and one behind Ballou Dam) were reported as >5 ppm and cannot be compared to the guideline for total PAH. Neither petroleum hydrocarbons nor polychlorinated biphenyls (PCB) were detected in the Yokum Brook sediment. Chlordane was detected in only one sample collected behind Ballou Dam. The concentration of chlordane did exceed the L-EL, however, the S-EL could not be calculated. Of the six metals analyzed arsenic and zinc concentrations were below the L-ELs in all samples analyzed. The cadmium samples were all reported as <1 ppm and the L-EL (0.6 ppm) is lower than the detection limit so no comparisons could be made. The concentration of three metals (copper, nickel and lead) in samples collected behind Silk Mill Dam slightly exceeded the L-ELs for those metals (one copper sample, two nickel samples and two lead samples). The concentrations in all of the other samples analyzed behind Silk Mill and Ballou dams were less than the L-ELs.
The Aquatic Life Use for Yokum Brook is assessed as support based primarily on the benthic macroinvertebrate community analyses and the fish population information. The presence of reproducing salmonids and other intolerant, fluvial specialists/dependants is indicative of excellent water quality and stable streamflow conditions.

Primary Contact and Secondary Contact RECREATION and Aesthetics

DWM collected fecal coliform bacteria samples from Yokum Brook at Route 8 bridge near Carter Road, Becket (Station YKMB00.2) in May and August 1996 (n=2) as part of the 1996 Westfield River Watershed monitoring survey (Appendix G, Table G4). Additionally, DWM collected a fecal coliform bacteria sample in May 1996 from a discharge pipe upstream from the Route 8 bridge, which was discharging to an unnamed tributary of Yokum Brook (Station TTYB00.0).
No objectionable odors, oils, deposits, turbidity or other conditions were noted by DWM biologists at any of the three stream reaches sampled in September 2001 in the lower portion of Yokum Brook (Stations YB01A, YB01B, or YB01C).
Too limited data are available so the Recreational uses for Yokum Brook are currently not assessed.

The Aesthetics Use is assessed as support based primarily on field observations by DWM biologists in 2001 and best professional judgment.

Yokum Brook (MA32-19) Use Summary Table

Aquatic Life	Fish Consumption	Primary Contact	Secondary Contact	Aesthetics
SUPPORT	Not Assessed	Not Assessed	Not Assessed	SUPPORT