Code of Maine Rules › 13 - DEPARTMENT OF MARINE RESOURCES › 188 - MARINE RESOURCES - GENERAL › Chapter 60 - RESOURCE MANAGEMENT PLAN › ATLANTIC SALMON MANAGEMENT IN THE KENNEBEC RIVER › Appendix 188-60-A - SUMMARY OF WATER QUALITY IN THE KENNEBEC RIVER BASIN

Current through 2024-29, July 17, 2024
Prepared for the Atlantic Sea-Run Salmon Commission by John
					 Bowles; Maine Department of Environmental Protection
January, 1986
At the request of the Atlantic Sea-Run Salmon Commission,
					 this water quality summary focuses on the Kennebec mainstem, Carrabassett
					 River, Sandy River, Wesserunsett Stream, and Sebasticook River. Based on
					 historical evidence showing that oxygen levels during winter did not present a
					 problem to fish, even before 1978, field data were collected only between May
					 and October. Occasionally some information is available on inorganic and
					 organic compounds. Water quality in the Kennebec River Basin has improved
					 dramatically since 1978 when most of the major discharges were treated for
					 biochemical oxygen demand (B.O.D.) wastes. Data collected during the summers of
					 1983, 1984, and 1985 indicate that dissolved oxygen levels in most of the
					 drainage exceed 80% saturation and 7.0 mg/1 during the hottest days of summer.
					 Exceptions do occur, however, which in some instances could limit use of
					 particular stretches of water by salmonids.
The Carrabassett River and its tributaries contain high
					 levels of oxygen (90% saturation). With the exception of Stanley Stream in
					 King-field, dissolved oxygen was never observed to fall below 7.0 mg/1 and
					 exceeded 22 C only on very warm days in the slower and wider portions. Stanley
					 Stream in Kingfield is now in the process of being cleaned up as the Town
					 constructs sewage treatment facilities. This should remove the only serious
					 source of B.O.D. containing wastes from Carrabassett. In the headwaters,
					 development, road building, and forest clearing has the potential of affecting
					 water quality in the Carrabassett. For example, turbidity and siltation in the
					 river increases sharply during heavy runoff events. While no obvious biological
					 affects have been noted, the overall biological impact is not yet known.
The mainstem of the Sandy River has no known significant
					 water quality problems based on samples collected from eight mainstem sites.
					 Dissolved oxygen remained above the 75% saturation level throughout the season
					 and biological monitoring indicated water quality was sufficient to support
					 aquatic life indigenous to the Sandy River. Four tributaries, however, have
					 depressed levels of oxygen considered marginal for salmonids. Cascade Brook,
					 Farmington and Wilson Stream, North Chesterville have oxygen concentrations as
					 low as 5.2 mg/1 and 61% saturation. Little Norridgewock Stream, Chesterville
					 has oxygen concentrations as low as 4.5 mg/l and 51% saturation. An unnamed
					 stream in New Sharon which drains a now closed out oxidation lagoon is
					 virtually anoxic during low flow and high temperatures. Minimum concentrations
					 typically occur in late summer. These tributaries, however, do not
					 significantly influence water quality in the mainstem of the Sandy River due to
					 their small flow relative to that of the Sandy River. With the exception of
					 these four tributaries, water quality in the Sandy River drainage is sufficient
					 to support salmonid populations.
Water quality in Wesserunsett Stream was sampled only at
					 one spot, near its confluence with the Kennebec River in Skowhegan. Dissolved
					 oxygen was consistently above 80% saturation and temperatures did not exceed
					 24° C.
The Sebasticook River and its East Branch continue to have
					 serious water quality problems. Between Newport and Clinton, summertime
					 dissolved oxygen frequently falls below 5.0 mg/1 and at times is less than 1.0
					 mg/1 at Detroit. Even at Winslow, dissolved oxygen is as low as 5.7 mg/l or
					 657% saturation. During the rest of the year dissolved oxygen in the East
					 Branch is considerably higher although it has been observed to be as low as 8.1
					 mg/1 on occasion outside the summer months. The segment below Newport should
					 improve markedly in 1986 when the town connects to its new treatment plant. An
					 unknown influence on water quality below Newport is the effect of the
					 Sebasticook Lake restoration project which involves a late summer drawdown. The
					 water released is typically rich in nutrients due to algae. Since algae are
					 also a source of B.O.D., night time oxygen levels below Newport may continue to
					 experience a depression. The actual amount of the depression can not yet be
					 predicted due to the overwhelming masking effect of Newport's presently
					 untreated wastes. Above Sebasticook Lake, between Corinna and the lake, fish
					 kills recently have been frequent. Benthic invertebrate analysis of that
					 portion of the river reveals a very serious chronic toxicity problem. The
					 segment below Corinna is now under study with toxicity tests being conducted to
					 locate the source of the problem. No prognosis for this stretch can be made.
					 Several tributaries to the East Branch Sebasticook also have poor water
					 quality. Stetson Stream, Martin Stream, Carleton Stream and Mill Stream all
					 experience low (less than 60%) dissolved oxygen levels in the summer.
The West Branch Sebasticook has no known problems even with
					 a tannery in its headwaters. Toxicity tests using
Daphnia
					 pulex
and
Ceriodaphnia reticulata
and
					 dissolved oxygen levels support the concept that water quality is sufficient to
					 support salraonids.