Water Quality Monitoring of
2008 was
the eighteenth consecutive year
of water quality monitoring conducted at Province Lake. We sampled four times last season. The test results for 2008 on water samples
collected by Steve & Mary Craig were reviewed by the New Hampshire Department of
Environmental Services
(NHDES). State reports for a number
of years are available by clicking this
web site.
Many of the
terms below include hyperlinks to
interesting related web sites. By
clicking on most of the underlined terms, you can access additional
information. If the same word is hyperlinked more than once, the
different occurrences
lead to different web sites. The
NHDES report on the quality of water in the lake for 2008 indicates the
following:
1. The
average amount of algae
in the lake in 2008 was virtually identical to that measured in the
previous
year, which itself was the lowest seen since 1999, as indicated by the chlorophyll-a
concentration. We have never returned to
the high levels observed during the weed removal activities of 1996 and
1997,
and their lingering effects in 1998. The
amount of algae is only 77% of the average for New
Hampshire lakes. This low level is
good because dying algae forms the brown floating bottom masses that
come to
your shore when the wind blows hard in July and August.
The algae masses settle loosely on the bottom
when the lake is still and cloud the water when wind
or boat wakes stir
things up.
2. Water
transparency (a
measure
of how deep you can see into the water) was an average of
The deepest
part of the lake is only 16—17 feet
deep, as shown on the bathymetric
chart.
3. Phosphorus
is a nutrient required for plant
and algae growth and is typically the nutrient whose availability
most
limits plant and algae growth in NH lakes.
The average phosphorus levels in the upper water layer in 2008
were also
virtually identical to those measured in the previous year and were
only
slightly higher than in 50% of the lakes
in NH
(the median). In the lower water layer,
the phosphorus levels were less than in the previous 3 years and were
approximately equal to the NH median, but significantly below the
median for
lakes in NH that are similar to
The phosphorus concentrations at the Rt. 153
Inlet
and the Island
Inlet on
4. We
have never sampled
5. Cyanobacteria
(also known as blue-green
algae) have occasionally been detected among plankton
samples in
If you
think you are seeing a bloom, stay out of
the water and call the NHDES
Cyanobacteria Hotline at (603) 419-9229 to
describe what you see. If suspicious,
NHDES will sample and analyze the suspected bloom, then post a No
Swimming
advisory if there is any danger. They
will monitor the situation and remove the postings when all is clear.
The best ways to avoid having cyanobacteria blooms are by eliminating
fertilizer use on lawns, keeping
the lake shore natural, protecting
against shoreline erosion, and properly maintaining septic
systems.
6. A
pH between 6.0
to 7.0
is ideal for fish. Ours in 2008 was an average of 6.5, almost
the same as the 6.6 average for the state.
The pH at
the Rt.
153 inlet was 5.7, more acidic than its long-term average of 6.0. Since it drains a large wetland,
it has a high concentration of tannic, humic, and fulvic
acids, which give it the color of tea and reduce its pH.
No problem is indicated.
7. The dissolved
oxygen
concentration measured in June 2008 showed 95 to 100% saturation
at all
depths sampled in the deep part of the lake.
A high oxygen level is a sign of the lake’s overall good health. I encourage powered watercraft to operate far
from the shore to mix the deep waters and boost the oxygen
concentration, while
minimizing their operation in the shallows.
Loons and
Lead: A recently
released study[i]
(in Northeastern
Naturalist, June 2009) addressed the ingestion of lead objects by
loons in
the six
Asian
Longhorned Beetle: The Asian Longhorned Beetle (ALB) is a
tree-killing beetle 0.75 -
1.
Please
always use local firewood, to keep from
spreading this beetle and other wood pests around.
There is a up to a $25,000 fine for
businesses knowingly removing wood from the Worcester quarantine area,
with
smaller fines for individuals moving wood for their personal use.
2.
Watch for
the beetle (July – October, most active in
August), and more importantly, for signs of it.
·
3/8 to 1/2
inch
diameter round exit holes, which may ooze sap
·
Sawdust in
tree
crotches
·
Tree leaves
with only the midribs eaten out
·
Trees dying
from the top down (since the beetles and their larvae start eating at
the top)
·
Firewood
with 3/8
to 1/2 inch diameter round tunnels through it, eaten out by the larvae
What
To Do:
·
If you
suspect
you see an Asian Longhorned Beetle, try to capture it.
Place it in a jar and freeze it to kill
it. It cannot bite you.
·
Write down
the
exact location where you found it, and at what date and time.
·
If you
suspect
you see tree damage from this beetle (but no beetle), write down the
location
of the tree and the nature of the damage.
Tie survey tape or string on the tree, if you can.
·
Call 866-702-9938
from anywhere in the northeast
·
NOTE that
all Asian
Longhorned Beetle infestations in the
·
You can
learn
much more at the following web sites:
http://www.massnrc.org/pests/alb/
http://www.uvm.edu/albeetle/
http://www.dontmovefirewood.org/
THANK YOU
NOTE:
I want to thank Steve Craig for taking
the lead on the sampling activity since 2004.
Each year the State report grades each sampling program and each
Respectfully
submitted,
Norm Dudziak,
P.E., I.M.
Independent
subconsultant
to full-service environmental consulting and engineering firm
ESS
Group, Inc.
The
views contained in this report are my personal views and do not
represent the
views of ESS
Group, Inc.
Province
Lake Statistics from Appendix
F of the State Report,
Which has Statistics for
|
Maximum
depth |
|
|
|
|
Average
depth |
|
|
|
|
Volume |
|
2.98
billion gallons |
|
|
|
|
|
1.58 square
miles |
|
Watershed
area[ii] |
|
|
7.30 square
miles |
|
Flush rate |
1.0 time
per year (annual outflow = lake volume) |
||
[i]
Pokras, Mark; Kneeland, Michelle; Ludi, Anna; Golden, Ethan; Major,
Andrew;
Miconi, Rose; and Poppenga, Robert H. “Lead
Objects Ingested by Common Loons in
[ii] Watershed area includes the lake surface area.