Water Quality

Analysis of Water Quality

In 2006, we resumed periodic monitoring of the water quality in the FLCA. At three-month intervals, we take samples from the Broad Brook at North Farms Road, from Fitzgerald Lake at the canoe launch and the dam, from the vernal pool adjacent to the Fishing Place Trail (spring only), and from two locations in the marsh adjoining Cooke’s Pasture to the east of the dam. We then analyze the samples for pH, alkalinity, and the concentrations of dissolved oxygen, phosphate and nitrate using simple chemical test kits. The data for 2010 are summarized in the following data files and tables:

Water Analysis at FLCA_2013 (MS Word document)

Water Analysis at FLCA 2012 (MS Word document)

Water Analysis at FLCA-April 2010 (MS Word document)

TABLES

April 17, 2010 (Williams, Zimmermann)

Location T (ºF) Dissolved 02 (ppm) pH Alkalinity
(ppm CaCO3)
Phosphate
(ppm)
Nitrate
(ppm N/NO3)
Ideal Range >6 6-7.5 100-200 <0.1 <0.1/<0.1
Brd Brk, E of NFR 45-50 12 7.0 27.4 0.06 0.22/0.97
Canoe Launch 45-50 10 7.0 41 0.06 0.08/0.35
Dam 45-50 11 7.0 20.5 0.04 0.01/0.04
Marsh, Beaver Lodge 45-50 9 6.8 27.4 0.04 0.01/0.04
Marsh, Guessing Pt. 45-50 9 6.8 27.4 0.10 0.01/0.04
Vernal Pool, Post 4 45-50 4 5.4 13.7 0.18 0.01/0.04

Notes
Dam: sample taken at dam outflow
Weather: overcast with showers, 40-45 ºF; intermittent showers during past 24 hr; no wind

March 7, 2009 (Williams, Zimmermann)

Location T (ºF) Dissolved 02 (ppm) pH Alkalinity
(ppm CaCO3)
Phosphate
(ppm)
Nitrate
(ppm N/NO3)
Ideal Range >6 6-7.5 100-200 <0.1 <0.1/<0.1
Brd Brk, of NFR 45-50 12 7.2 34.2 0.o7 0.44/1.94
Canoe Launch 45-50 12 7.2 41 0.07 0.20/0.88
Dam 45-50 11 6.7 34.2 0.08 0.08/0.35

Notes
Dam: sample taken at dam outflow
Weather: sunny, 45-50  ºF; lots of melt water; no significant pptn since snow storm on 3/2/09

June 4, 2009 (Zimmermann)

Location T (ºF) Dissolved 02 (ppm) pH Alkalinity
(ppm CaCO3)
Phosphate
(ppm)
Nitrate
(ppm N/NO3)
Ideal Range >6 6-7.5 100-200 <0.1 <0.1/<0.1
Brd Brk, NFR 60-70 10 7.2 34.2 0.06 0.82/3.61
Canoe Launch 60-70 9 7.4 54.7 0.04 0.22/0.97
Dam 60-70 8 7.2 34.2 0.06 0.03/0.13
Marsh, site 1 60-70 8 7.2 34.2 0.08 0.03/0.13
Marsh, site 2 60-70 6 6.8 34.2 0.08 0.02/0.09
Vernal Pool 60-70 3 5.7 13.7 0.34 0.02/0.09

Notes
Dam: sample taken at dam outflow
Weather: sunny, 60-70 ºF; no precipitation in past 24 hr
Vernal Pool: did not dry out over winter of 08-09

September 26, 2009 (Williams, Zimmermann)

Location T (ºF) Dissolved 02 (ppm) pH Alkalinity
(ppm CaCO3)
Phosphate
(ppm)
Nitrate
(ppm N/NO3)
Ideal Range >6 6-7.5 100-200 <0.1 <0.1/<0.1
Brd Brk, E of NFR 45-50 9 7.2 41 0.08 0.50/2.2
Canoe Launch 45-50 4 6.4 41 0.12 0.02/0.09
Dam 45-50 8 7.1 41 0.02 0.02/0.09

Notes
Dam: sample taken at dam outflow
Weather in preceding 24 hr: clear, T ranged from 35-65 ºF, no rain

December 6, 2009 (Williams, Zimmermann)

Location T (ºF) Dissolved 02 (ppm) pH Alkalinity
(ppm CaCO3)
Phosphate
(ppm)
Nitrate
(ppm N/NO3)
Ideal Range >6 6-7.5 100-200 <0.1 <0.1/<0.1
Brd Brk, E of NFR 30-34 9 7.1 27.4 0.06 0.32/1.41
Canoe Launch 30-34 10 7.1 34.2 0.06 0.08/0.35
Dam 30-34 9 7.1 34.2 0.04 0.02/0.09
Marsh, site 1 30-34 12 6.9 27.4 0.06 0.01/0.04
Marsh, site 2 30-34 10 6.2 20.5 0.08 0.01/0.04

Notes
Weather in preceding 24 hr : cloudy T in upper 20’s & lower 30’s ºF; light snow and rain
Water levels high throughout: culvert under NFR, canoe launch, marsh

The pH, alkalinity and levels of dissolved oxygen, nitrates and phosphates in the lake and the marsh have been normal for the past three years and signal a generally healthy aquatic environment. However, we have consistently found that the nitrate concentration in the Broad Brook at North Farms Road exceeds that considered favorable for fish and other aquatic life. Subsequent sampling indicated elevated nitrate concentrations further upstream as well. High nitrate levels can lead to eutrophication, a process in which the nitrates stimulate the growth of plants and algae that eventually settle to the lake floor and are decomposed by bacteria. The heightened bacterial activity in turn consumes oxygen, reducing the dissolved oxygen available to fish and aquatic invertebrates. Our measurements indicated nitrate concentrations of 1.5-4 parts per million (mg/L) in the Broad Brook, depending on the season. This is a red flag given that the desirable level for healthy fresh-water aquatic life is less than 0.1 parts per million. So far, the concentration of dissolved oxygen in the lake has remained at normal levels, but continued monitoring will be necessary to make sure that it does not decline.

The presence of nitrate in the Broad Brook likely stems, at least in part, from a storm drain system that serves a large portion of Florence, extending well into the neighborhoods along Bridge Street, North Maple Street and Country Way. However, further inspection revealed high nitrate levels in some of the Broad Brook’s tributaries that drain the Spring Grove Cemetery and the JFK Middle School. According to Doug McDonald, environmental planner and stormwater coordinator at the Northampton DPW, nitrates can come from any one of a number of sources, including fertilizer runoff, leaky septic systems, springs and groundwater flows. Two years ago, McDonald, together with BBC member Andrew Grimaldi and a group of middle-schoolers from the neighboring community, placed cautionary labels on the storm drains that connect into the Broad Brook under North Farms Road, alerting passers-by to the fact that what goes into the drains ultimately comes out in Fitzgerald Lake. At the same time, McDonald has been working with the staff at Spring Grove Cemetery to limit fertilizer use and check the integrity of their drainage system. In addition, we urge landowners in the Broad Brook drainage basin to limit their fertilizer use and have their septic systems checked on a regular basis. Further testing will be necessary to pin down the source (or sources) of the excess nitrate.