HomeMy WebLinkAboutHummock Pond Annual Report 2007_201401221138399015
Hummock Pond
Annual Report
2007
Prepared for:
Marine and Coastal Resource Department
34 Washington Street
Nantucket, MA 02554
Prepared by:
Keith L. Conant
Town Biologist
March 2008
Introduction:
Hummock pond is a eutrophic coastal pond located on the southwest side of
Nantucket Island. Hummock is approximately 2.3 miles long, running north to south
with an average depth of 6ft. The watershed to pond ratio, at an average is 15:1. The
pond is approximately 142 acres in size with a surface drainage basin of approximately
2,227 acres and a groundwater drainage basin of approximately 2,000 acres. Hummock
Pond accumulates water during the winter and generally floods in the spring. Flooded
conditions of Hummock Pond can reach Millbrook Swamp to Madaket Road. During
flooded conditions, the surface area of the pond increases from 140 acres to
approximately 425 acres (Kortman and Knoecklein 1994). Hummock Pond is opened to
the sea twice per year to alleviate flooded conditions and to enhance marine fisheries. In
addition, pond openings decrease nutrient concentrations and remove organic matter that
accumulates in the pond from the bordering wetlands.
The surface drainage basin extends north and east of the head of Hummock. The
basin encompasses Maxy’s Pond, Crooked Lane, and one third of Sunset Hill. The
surface divide extends south to Academy Hill School, “Five Corners”, part of Prospect
Cemetery, and encompasses Burnt Swamp. The surface divide then follows the
configuration of the pond to Cisco Beach extending just north of Hummock Pond Road
(Horsley, Witten and Heggemen 1990).The groundwater drainage basin starts north of
Rams Pasture and follows in a northward direction reaching Capaum Pond. The divide
stretches east to West Chester Street encompassing “No Bottom Pond” and to the
southwest through Burnt Swamp, Rotten Pumpkin Pond, and Larrabee Swamp and to
Cisco Beach. There are two soil types in the watershed that determine permeability and
eroding capability. The northern section is classified as “Medisaprists-Barryland Variant
association”, consisting of organic mucky deposits, combined with outwash soils that are
poorly drained. The southern section is classified as “Evesboro association” defined by
gently sloping sandy soils that drain rapidly.
Accelerated eutrophication of the pond in recent years has lead to harmful blue-
green algae blooms, and macro algae blooms. Dense mats of Enteromorpho intestinalis
in the summers of ’02, and ’03 impeded navigation and raised concerns of local residents,
as to the health of the pond. Because of this a more in depth and recent study was
required. George Knoecklein of Northeast Aquatic Research, LLC, a limnological
consultant for the Nantucket Marine and Coastal Resources Department, who had done
previous studies on the pond was hired to complete a two year evaluation. In
corroboration with Marine Dept. personnel Tracy Curley, and Keith Conant, Knoecklein
investigated nutrient loading aspects, water quality, and the effectiveness of pond
openings with respects to mitigating the ponds current problems. Copies of this report,
Hummock Pond 2005 Monitoring Report, by Dr. Knoecklein can be obtained at the
Nantucket Marine Department, 34 Washington St.
The School for Marine Science and Technology (SMAST), which is heading up
the Massachusetts Estuaries Project for the Department of Environmental Protection will
also be performing studies on the pond. 2007 investigations have been completed, and
include sediment cores for nutrient analysis, stream gauging, and a bathymetry analysis.
This work was completed with help from Marine Department personnel. This intensive
study has generated volumes of data, which will be analyzed in 2008 with the goal of
providing the Town of Nantucket a Total Maximum Daily Load (TMDL) scenario;
similar to the reports done for Nantucket Harbor, Sesachacha Pond, and the Madaket
Harbor / Long Pond system.
Methods:
Hummock Pond was monitored from April to November this year. Physical
parameters include, temperature, dissolved oxygen, salinity, secchi disk depth, and water
depth. Chemical parameters include nutrient concentrations of inorganic and organic
components, Nitrate (NO3), Ammonia (NH3), Kjeldhal Nitrogen (TKN), Total Nitrogen
(TN), and Total Phosphorous (TP). Nutrients were not analyzed in November due to
monetary constraints. In 2004, 9 sampling sites were established for the Knoecklein
study. Sites 1-6 remained the same, with a re-ordering of site 7, and the creation of sites
8, and 9. In 2007 sites 1, 3, 6, 7, and 8 were measured for physical parameters, additional
water samples were collected for chemical constituents at sites 1, 3, and 7. The water
samples are processed by Envirotech Laboratories located in Sandwich, MA. for the as
for mentioned nutrient constituents.
Hummock water quality sampling stations are as follow: Site 1: is located at the
foot of Hummock Pond. This site is closest to the ocean and generally remains brackish
throughout the year. The average depth is approximately 9ft. The bottom sediment is
sand. Site 3: is northward in a wider section of the pond. The water depth is
approximately 6ft. The bottom sediment is sand and mud. Site 6: is located at the base
of the northern bay. The average depth at this site is 4 ft., and the bottom is mud and
detritus. Site 7: is located in the north head of hummock which is connected to the main
body of the pond by a small winding tributary. The average depth at this site is 12 ft.,
and the bottom is a flocculent muddy surface approximately 6” deep covering a mud
bottom. Site 8: is located at the northeast headwater of the northern bay, where there is
an inlet from a sub-watershed to the northeast. The average depth is 4 ft., and the bottom
is detritus, and flocculent mud. These locations are designated on Map #1.
Water Quality Monitoring Results:
Appendix A: contains all physical and chemical water quality data. Appendix
B: contains the averages of A with corresponding charts. Appendix C: contains average
monthly rainfall for 2006, as collected by the Nantucket Water Company.
Temperature and Dissolved Oxygen:
Temperature and dissolved oxygen are often closely related, and inversely
proportional. The solubility of oxygen in water is very dependant on the temperature,
and will decrease as temperature rises. Dissolved oxygen (D.O.) is also affected by
nutrients, and the biological oxygen demand (BOD) of decaying plant or animal matter.
As nutrients increase, phytoplankton and macro algae increase proportionately. These
plants have a relatively short life cycle, and when they die and sink to the bottom, they
are consumed by bacteria. These bacteria consume oxygen, and may lead to anoxic
events. When this occurs, nutrients are released from the sediments, and a process
known as “internal recycling” begins. The process of eutrophication may occur naturally,
but at Hummock Pond it is accelerated by anthropogenic uses.
The temperature in Hummock Pond follows a well defined cyclical seasonal
pattern, which is shown by the bell curve graph in figure 1. The pond is relatively
isothermic because of its shallow condition and elongated shape, which allows it to be
well mixed by wind driven waves. However because it is so long there are some
differences between the foot and the head. These differences are also affected by surface
water runoff, groundwater intrusion, and salinity gradients. The isolation of the northern
head, its depth, and its kettle shape create the greatest variances. July and August are
typically the months where temperatures reach their highest points. Fortunately in 2007
the main body of the pond did not go above 24ºC, or 75ºF (Appendix A, & Figure 1).
This may decrease the solubility of oxygen in the water column, however it would not
normally create an anoxic condition. The highest recorded temperatures occurred in the
northern reaches of the pond at Site 7, and were just above 24ºC in august. For the most
part there was limited stratification, with very subtle effects from a mild turnover during
the winter, due to limited ice formation.
Dissolved oxygen (D.O.) concentrations are at maximum in the winter, due to
cooler water temperatures. The main body of the pond experiences lower dissolved
oxygen concentrations during the summer months where the concentrations typically
range between 4 mg/l and 6 mg/l. D.O. conditions during the 2007 sampling period were
better than most years, probably due to cooler temperatures and lack of precipitation that
would normally bring a lot of nutrients to the pond. The lowest dissolved oxygen
readings taken are associated with Site 7, and are related to the eutrophic conditions that
exist there (Appendix A). The lowest recorded value throughout the main body of the
pond occurred at the bottom at Site 1 in May after the ocean exchange had been met.
This value of 4.05 mg/l was still not into a dangerous hypoxic level, and was probably
related more to the salinity change at 9 feet. Site 7 shows a problematic condition
throughout the sampling period. Initial bottom readings are in the hypoxic range, and by
June they begin to show a trend toward a hyper eutrophic state (Appendix A, & Figure 2).
By August bottom readings are 8.85 mg/l, coinciding with a massive blue green algae
bloom throughout the water column; which also extends into the channel that connects
the North Head with the Northern Bay. By September, bottom conditions have gone
anoxic, 0.68 mg/l, as the full effect of the algae bloom takes hold. It is during these
anoxic events that even more nutrients are released from sediments on the bottom, further
exacerbating enriched conditions. As a consequence the algae bloom concentration
increases, and lasts through to October; a duration of 3 months. Following the fall
opening, and with the onset declining temperatures, D.O. conditions improve in
November.
Figure 1: Average Temperature 2007
Average Temperature
5.0
10.0
15.0
20.0
25.0
30.0
April May June July Aug Sept Oct Nov
Month SampledDegrees CelsiusSite 1
Site 3
Site 6
Site 7
Site 8
Figure 2: Average Dissolved Oxygen 2007
Average Dissolved Oxygen
2.00
4.00
6.00
8.00
10.00
12.00
April May June July Aug Sept Oct Nov
Month SampledD.O. (mg/l)Site 1
Site 3
Site 6
Site 7
Site 8
Salinity:
Hummock Pond has been designated to be maintained as a brackish water pond
for fisheries migrations, mitigation of water quality and flood control by mechanically
breaching the natural barrier beach to the ocean in the spring and fall. The 2007 spring
opening occurred 4/20, and remained opened until 4/30, the fall opening occurred 10/26
and remained open until 11/2. Spring openings typically last longer than fall openings
because of head waters accumulated during winter and spring precipitation. However, if
a spring opening is not met for at least a week then water quality usually declines
throughout the summer. During the spring opening, the ocean typically fills
approximately half the pond (site 1 to site 6). Groundwater and surface water fill the
head of the pond (site 6 to site 7, and 8). After an opening, mixing slows down and a
salinity gradient develops in the pond forming a wedge. The foot of the pond retains the
highest salinity while the head continues to become fresh from the constant input of
groundwater. Hummock pond, located in the outwash plains, cannot maintain saline
conditions due to the physical configuration of the pond, with respect to its watershed.
Hummock contained an average salinity of (4.9 ppt) in April prior to the spring
pond opening. The pond increased in average salinity to 9 ppt after the opening. There
were of course differences between the foot and the North head, prior to, and after the
opening (Appendix A, & Figure 3). These differences were greatest (9.7 ppt) between
the foot and head following the closure. As the pond began to seek equilibrium, a well
defined salt wedge began to form at Sites 7, and 8 in June. The length of time the pond
remains open to the ocean usually determines the initial salinity change in the pond.
Salinity decreased throughout the summer as the pond filled with groundwater; this was
delayed this year by the lack of precipitation over the summer. Site 8 actually showed a
slight increase in salinity in July. Signs of freshening occurred first at Site 7 in May, and
then Site 8 in June, as groundwater inputs from the northern watershed drive the recharge
of the pond. The lowest salinity reading taken on the pond was at Site 7 throughout the
water column in October, at (2.3 ppt).
The average pond salinity was 3.9 ppt in October prior to the fall opening. When
the pond closed on 10/29, it closed on a low tide, however with a higher average salinity
than the spring opening. A combined affect of this was higher salinities throughout the
entire pond. Bottom measurements at the foot and the head were recorded at 14.4 ppt for
Site 1, and 9 ppt for Site 7. Top to bottom differences were only, as much as 3 ppt (Site
7). The salinity in the pond was much greater after the fall opening of 2006, than the fall
opening of 2007.
This extensive flushing should help to reduce nutrient levels in the pond,
temporarily alleviating eutrophic conditions. If this is true, then water quality conditions
for the summer of ’08 should be good, or at least better, and the pond should exhibit
mesotrophic conditions. Blue-green algae blooms, and nuisance macro algae growth
should also be minimized. However if this is not the case, then another form of
remediation must be met in order to restore the ponds water quality. The success of
openings can not be guaranteed, and the exportation of the nutrients which cause the
problem, is not necessarily the best strategy. In fact the opening of a coastal pond to the
ocean is very disruptive to the ecological community within. Following the last openings
in 2006, where an excellent exchange of sea water was met, there was still a blue - green
Algae bloom that lasted 3 months in 2007. This would indicate that opening the pond to
the ocean is not enough to restore water quality. For, even in a record dry summer, 2007,
the draw down of groundwater and turbidity of organics from openings led to high
nutrient loading, and harmful algal blooms. Hopefully though, the openings will at least
be beneficial to the herring population recovery; a species which has received a no
fishing prohibition by the Division of Marine Fisheries until 2009.
Figure 3: Average Salinity 2007
Average Salinity
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
April May June July Aug Sept Oct Nov
Month Sampled(ppt)Site 1
Site 3
Site 6
Site 7
Site 8
Rainfall:
Average rainfall was collected by the Nantucket Water Company, and shows
record low precipitation for the summer, and low precipitation for the year (Appendix C,
& Figure 4). As previously discussed rainfall directly affects volume and salinity in the
ponds. It also affects the amount of nutrients that are carried in surface water and
groundwater flow from watersheds to their associated water bodies. As anthropogenic
uses increase, rainfall becomes an important factor in determining water quality.
Figure 4: Average Monthly Rainfall 2007
Average Monthly Rainfall
0
1
2
3
4
5
6
7
JanFebMarAprMayJunJulAugSept OctNovDecMonthInches Inches
Total Rainfall = 28.89”
* December rainfall incomplete
Rainfall data supplied by Wannacomet Water Company
Secchi Disk Depth:
Secchi disk depth recordings are a quick helpful test in measuring water clarity.
Water transparency will indicate the amount of phytoplankton, algae, and therefore
nutrients available in the water column. The disc measures roughly one half the visible
light penetrating the water column. When you combine this information with the
bathymetry of any given water body, you can roughly define submerged aquatic
vegetation boundaries. Because of Hummock Pond’s average shallow depth, bathymetry,
and poor water quality, it has a relative high abundance of submerged aquatic vegetation;
some of which is undesirable. Secchi disk depth recordings reflect this condition,
however this year they were better than most (Appendix A, & Figure 5). The salinity
appears to be too low to effectively wipe out phragmities, and too low to support eel
grass. Because of this however, the pond does support an abundant and diverse
population of pond weeds. However, with nutrient levels as high as they are, Hummock
has had problematic episodes of nuisance vegetation, and had deleterious phytoplankton
blooms of blue-green algae which may dominate an ecosystem.
Average secchi disk depth recordings were (0.5 ft.) higher in 2007 than 2006,
probably due to the lack of precipitation and associated nutrient loading. The 3 ft.
average for most of the sampling period indicates a high level of phytoplankton
production. Also in some shallow Sites, 3, 6, and 8 pond weeds were so thick they
interfered with disk readings. Site 7 experienced its lowest reading in September at 1.5
ft. This was the result of a shift in phytoplankton communities, as blue-green algae
became dominant June. The highest recordings were taken at Sites 3, and 1 in October;
and measured to 6ft and 5.5ft respectively. This was most likely due to the lack of
precipitation, the settling effect after the opening, and the cooling temperatures. These
secchi disk depths for 2007 are still low however, and do not reflect an improvement in
water quality.
Figure 5: Secchi Disk Depth 2007
Secchi Disk Depth
0
1
2
3
4
5
6
7
April May June July Aug Sept Oct Nov
Month SampledFeet Site 1
Site 3
Site 6
Site 7
Site 8
Pond Elevation:
Pond elevations were recorded on a pole between Sites 3, and 4 on the east side of
the pond, at an abandoned floating dock location. The pole was chosen in 2004 for the 2
year Knoecklein (Northeast Aquatic Research) study. It was used in cross reference with
topographical contours to measure pond volume with respects to mean sea level (MSL)
elevation. With many years of data an average pond volume may be acquired with the
use of the elevation at the pole. The 2005 report showed that the ponds surface area was
142 acres when the pole elevation was 3 ft., and this appears to be the average volume.
At 5 ft. the pond would be at a somewhat flooded condition, with a surface area coverage
of 267 acres. The base of the pole is approximately 0.5 ft. above mean low water sea
level. This was determined by measurements taken 11/1/07, during the ’07 fall opening.
So with a pole elevation of 2 ft., the surface of the pond would meet mean sea level.
When the pond was opened in April, it was approximately 5ft. (Appendix A, and
Figure 6). The pond closed on a low tide, but was soon filled to 3.5 ft. with fresh
groundwater from winter and spring precipitation. As precipitation dropped off in the
summer so did elevation at the pole, approximately 2.2 ft by September. The pole
elevation combined with salinity also shows that the pond is continually freshening,
despite precipitation. As precipitation picked up in September, pond elevation rose
slightly. However, after the fall opening, which closed on a low tide, the pond elevation
was down again; just below 2 ft. in November. This shows the pond closures taking
place at MSL, following both spring and fall openings.
Figure 6: Pond Elevation at Pole 2007
Pond Elevation at Pole
0
1
2
3
4
5
6
April May June July Aug Sept Oct Nov
Month SampledFeet Feet
Nutrients:
Nitrogen:
Nitrogen is the limiting nutrient in marine ecosystems, the quantity of which will
dictate the health of any particular water body. Because Hummock is opened to the
ocean it maintains a brackish water system for much of the year. Nitrogen which is
accumulating in Hummock Pond may have a greater negative effect toward the foot of
the pond than the head. Because of the ponds shape, there exists a higher saline condition
at the foot, and a greater fresh water recharge at the head. Total nitrogen includes both
organic and inorganic components. The Department of Environmental Protection for
Massachusetts uses some standard classifications based on nitrogen thresholds to describe
the health of many marine ecosystems. Hummock is now classified as an impaired, or
eutrophic water body. Total nitrogen above 700 ppb is considered eutrophic. These
standards can be found in the Estuaries Project Interim Report 2003, prepared by the
School for Marine Science and Technology.
Total nitrogen when sampling began in April was very low, almost below a
reportable limit. This may however have been due to colder temperatures, and an
inactive environmental condition at this time. TN quickly reached exceedingly high
levels after the spring opening in May, and may have been influenced by draw down
effect of nutrient laden groundwater as well as increasing temperatures. Sites 1 and 3,
were above 1,000 ppb and Site 7 was above 2,000 ppb TN (Appendix A, & Figure 7).
Site 7 peaked in August with a reading of 2,670 ppb TN, in conjunction with the onset of
the blue-green algae bloom. This reading is close to four times greater than the level
suggested to be the limit to induce eutrophication in a marine system. And though Site 7
is predominantly fresh, this probably contributed to the anoxic conditions that occurred
there in September and October. Anoxic events negatively affect an area because they
allow for the re-release of nutrients from soils back into the water column. These
nutrients then produce more harmful algae blooms in a never ending cycle toward
etrophication, as bacteria consume the decaying algae on the bottom decreasing dissolved
oxygen in a process known as biological oxygen demand (BOD), re-creating anoxic
conditions on an annual cycle.
Also high at times were the various organic, and inorganic components of TN,
such as Nitrate (NO3), Kjeldhal Nitrogen (TKN), Ammonia (NH3), and Organic
Nitrogen (ON); see (Appendix B) for tables and figures. Eutrophic limits for these
constituents are as follows; (NO3) 70 ppb, (TKN) 700 ppb, (NH3) 50 ppb, and (ON) 700
ppb. The large exchange that occurred in the fall opening was expected to decrease
nitrogen levels for the summer of 2007, as long as pond temperatures remained cool, and
anoxic events were avoided. This may be even more evident as the summer of 2007 was
a record dry one, with little precipitation to carry nutrient rich surface water and
groundwater from the watershed to the pond. However this was not the case, and would
suggest that other means of controlling nitrogen levels must be met in order to ensure the
future health of the pond.
Figure 7: Total Nitrogen 2007
Total Nitrogen TN
0
500
1000
1500
2000
2500
3000
April May June July Aug Sept Oct Nov
Month Sampled(ppb)Site 1
Site 3
Site 7
Total Phosphorus:
Hummock pond is predominantly a fresh water system because of its elongated
shape, watershed area, and fresh water inputs on its northern end. The foot of the pond
does remain brackish for much of the year though, and this does create some interesting
dynamics. Total phosphorous (TP), is predominantly the limiting nutrient for plant
growth in a fresh water system. However there is most likely a flip flopping of nutrient
limiting conditions, because of salinity changes; based on nitrogen phosphorous ratios.
This is usually the case in most coastal ponds that are opened to the ocean, and as
previously discussed when this pond is transformed into a marine system, nitrogen
becomes the limiting nutrient. Total phosphorous levels at or between 15-25 ppb, would
be indicative of a mesotrophic system with good to fair water quality. Phosphorous
levels rising above 50 ppb indicate eutrophic conditions.
The majority of water samples taken at Hummock for the summer of 2007
indicate eutrophic conditions with respects to phosphorous. All samples taken at Site 7
are above the impaired level. Two samples are 14 times the eutrophic limit, taken in,
September and October; showing 733 ppb and 703 ppb (Appendix A, & Figure 8). Site
1, the area with the most saline conditions showed the lowest average TP for 2006.
However the May and July readings at Sites 1 were high, double the eutrophic limit. Site
3 showed a higher average TP than Site 1, but varied dramatically from month to month.
This may be related to influences from the Head of Hummock, as the flow of water
appears to move from the head to the foot of the pond. The graph shows a sharp increase
in TP at Site 7 with the onset of July, which coincides with peaking temperatures and
hyper-eutrophic D.O. conditions; as well as declining salinities (Appendix A). By
September periods of anoxia at site 7 result in a release of phosphorous from bottom
sediments. This was visually seen from the physical presence of the blue-green algae
bloom witnessed in the north head, which continued into October. Following the fall
opening in October, it was predicted that the TP dropped off with the exchange to the
ocean increasing salinities, and D.O. recordings, and falling temperatures. Also by the
November sampling round the blue-green algae bloom had completely dissipated.
Figure 8: Total Phosphorous 2007
Total Phosphorous TP
0
100
200
300
400
500
600
700
800
April May June July Aug Sept Oct Nov
Month Sampled(ppb)Site 1
Site 3
Site 7
Conclusions:
The summary of results from the 2007 sampling period reveal that elevated levels
of nutrients are occurring throughout Hummock pond. The highest concentrations of
which are occurring in the northern head, which then affect lower portions of the pond.
Nutrients are entering the pond from atmospheric deposition, septic and fertilizer inputs
from the watershed, and internal recycling during anoxic events. The opening of the
pond to flush nutrients does not appear to be a working solution, and the mitigation of
nutrients in the form of sewer installation or changes in anthropogenic uses will not be
resolved in the near future. In Knoecklein’s 2005 report on Hummock, aeration is
suggested as a possible solution to eliminate anoxia in the north head of Hummock in
order to eliminate the recycling of nutrients during anoxic events. Also suggested is, the
mechanical harvesting of weeds, a process that will have to be repeated as necessary.
Both options should be considered, however the only long term solution is to mitigate
nutrients in the watershed before they reach the pond.
The School for Marine Science and Technology (SMAST), is concluding their
nutrient studies of the pond in cooperation with the Nantucket Marine Department.
These studies will evolve into a more thorough Total Maximum Daily Load (TMDL)
scenario, in accordance with the Massachusetts Estuaries Project, overseen by the
Department of Environmental Protection. The comprehensive waste water treatment plan
being evaluated by Earth Tech and the Nantucket Department of Public Works will also
help come up with solutions to mitigate nutrient enrichment in Hummock. Until then,
the opening of Hummock Pond, which may not definitively improve water quality will
continue. Opening Hummock Pond for flood control and marine fisheries also needs as
much attention as water quality monitoring. Their benefits and effectiveness need to be
gauged quantitatively against their potential negative effects.
Appendix A
Hummock Pond
2007
Physical and Chemical Data
Site 1: Foot of Pond
Site 3: Middle of Pond / Top of Main Body
Site 6: Northern Bay
Site 7: North Head
Site 8: North East Cove of Northern Bay
Temperature (º C)
Site 1 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 6.7 14.4 19.7 21.6 23.7 19.7 16.4 5.4
3 6.6 14.3 19.8 21.6 23.7 19.6 16.4 5.3
6 6.6 14.3 19.8 21.6 23.7 19.6 16.3 5.2
9 6.6 13.5 19.8 21.5 23.6 19.6 16.3 5.2
11 6.6 19.8 21.3 23.6
Site 3 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 7.2 14.8 19.1 21.5 23.7 19.9 16.3 5.6
3 7.2 14.8 19.2 21.5 23.8 19.9 16.3 5.6
6 7.2 14.7 19.2 21.5 23.7 19.8 16.2 6
7 7.2 14.6 19.2 21.5 23.7 16.2
Site 6 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 7.8 15.7 19.2 22.2 23.5 20.1 16.6 5.7
3 7.9 15.7 19.3 22.2 23.5 20 16.6 6.1
6 7.7 15.7 19.3 22.3 23.5 20 16.6 6.2
Site 7 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 7.3 15.6 19.4 22.2 24.1 20.1 16.7 6.1
3 7.3 15.6 19.4 22.2 24.1 20 16.6 6.1
6 7.3 15.5 19.3 22.2 24.1 19.9 16.5 6.7
9 7.3 15 19.5 22.1 24.1 19.9 16.4 6.5
12 7.3 14.6 19.1 22.1 24.1 19.7 16.4 7
13 7.2
Site 8 4/12/2006 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 8.2 15.8 19.1 22.4 23.6 20 16.6 6
3 8.2 15.4 19.1 22.5 23.6 20 16.5 6.2
5 8.2
Dissolved Oxygen (mg/l)
Site 1 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 11.12 8.67 7.31 7.47 7.61 7.97 8.68 11.53
3 11.15 8.64 7.25 7.27 7.57 7.89 8.68 11.42
6 11.14 8.65 7.27 7.26 7.61 7.91 8.67 11.45
9 11.16 4.05 7.31 7.12 7.62 7.75 7.88 11.35
11 10.94 7.32 6.23 7.51
Site 3 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 11.12 8.58 7.3 8 7.7 8.09 8.46 11.13
3 10.96 8.57 7.24 7.94 7.62 8.09 8.39 11.2
6 10.95 8.42 7.23 7.65 7.6 8.08 8.37 11
7 10.84 8.35 7.16 7.47 7.49 8.25
Site 6 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 10.36 8.07 6.79 7.1 7.6 7.63 8.32 11.05
3 10.34 8.01 6.71 7.08 7.54 7.6 8.27 11.02
6 10.06 8.01 6.56 5.67 7.41 7.59 8.24 10.94
Site 7 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 11.22 10.12 8.14 9.13 9.84 8.91 9.08 12.13
3 11.13 10.15 8.04 9.1 9.64 8.92 8.97 12.15
6 11.16 10.22 8.01 8.99 9.66 8.97 9.04 11.22
9 11.19 7.66 4.06 8.96 9.68 8.99 8.87 10.1
12 10.95 3.18 2.05 4.54 8.85 0.68 1.67 8.13
13 2.87
Site 8 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 9.65 8.23 5.43 5.95 6.09 7.01 7.97 10.37
3 9.58 6.72 5.35 5.35 5.8 6.86 7.83 10.94
5 9.17
Salinity (ppt)
Site 1 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 5.5 13 8.7 8.2 6.8 5.7 5 14.4
3 5.5 13 8.7 8.2 6.8 5.7 5 14.4
6 5.5 13.1 8.7 8.2 6.8 5.7 5 14.4
9 5.5 15 8.7 8.2 6.8 5.7 5 14.4
11 5.5 8.7 8.2 6.8
Site 3 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 5.3 12.7 8.6 7.6 6.6 5.6 4.9 14.4
3 5.3 12.8 8.6 7.6 6.6 5.6 4.9 14.4
6 5.3 12.8 8.6 7.7 6.6 5.6 4.9 14.6
7 5.3 12.8 8.6 7.7 6.6
Site 6 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 4.7 11.2 7.5 6.7 5.2 4.3 3.8 13.4
3 4.7 11.2 7.5 6.7 5.2 4.3 3.8 13.7
6 4.8 11.2 7.5 6.7 5.2 4.3 3.8 13.8
Site 7 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 4.5 3.6 4.4 4.2 3.3 2.7 2.3 6
3 4.5 3.6 4.4 4.2 3.3 2.7 2.3 6
6 4.5 3.6 4.4 4.2 3.3 2.7 2.3 6.7
9 4.5 4.7 5.3 4.2 3.3 2.7 2.3 8.6
12 4.5 5.7 5.8 4.3 3.4 3 2.3 9
13 4.5
Site 8 4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
0 4.6 4.1 5.43 6.7 4.9 4.1 3.5 11.3
3 4.6 7.1 5.35 6.7 4.9 4.1 3.5 13.4
5 4.6
Secchi Disk Depth
(ft.)
4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
Site 1 3 2 4 3 4 4 5.5 4.5
Site 3 2.5 2 4 3.5 3 5 6 4
Site 6 3 1.5 2 2.5 2.25 2 3 3.3
Site 7 2.5 2.5 4 3 2 2.5 2.8 4.1
Site 8 2.5 2 2 2.5 1.6 1.5 3 2.2
Pond Elevation at Pole (ft.)
4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
Feet 5 2 3.5 3.3 3 2.2 2.6 1.8
Nitrate (NO3 ppb)
4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
Site 1 BRL BRL 10 10 10 BRL BRL
Site 3 BRL 10 <10 BRL 10 BRL BRL
Site 7 BRL BRL 130 BRL 10 BRL 10
Ammonia (NH3 ppb)
4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
Site 1 50 150 280 130 90 120 100
Site 3 40 550 160 80 70 130 90
Site 7 40 90 110 130 60 100 50
Kjeldhal Nitrogen (TKN ppb)
4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
Site 1 BRL 1,190 560 1,050 700 770 910
Site 3 BRL 1,120 210 700 980 630 700
Site 7 BRL 2,800 210 770 2,660 1,400 1,470
Organic Nitrogen (TKN - NH3 = ON ppb)
4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
Site 1 BRL 1,040 280 920 610 650 810
Site 3 BRL 570 50 620 910 500 610
Site 7 BRL 2,710 100 640 2,600 1,300 1,420
Total Nitrogen (TN
ppb)
4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
Site 1 <100 1,190 570 1,060 710 770 910
Site 3 <100 1,130 210 700 990 630 700
Site 7 <100 2,280 340 770 2,670 1,400 1,470
Total Phosphorous (TP ppb)
4/12/2007 5/9/2007 6/12/2007 7/3/2007 8/9/2007 9/25/2007 10/22/2007 11/20/2007
Site 1 32 104 63 112 BRL 46 42
Site 3 70 135 80 87 99 37 41
Site 7 78 147 82 204 673 733 703
BRL = Below Reportable Limit
ND = Not Detected / Below Detectable Limit
Appendix B
Hummock Pond 2007
Average Physical and Chemical Data with Charts
Site 1: Foot of Pond
Site 3: Middle of Pond / Top of Main Body
Site 6: Northern Bay
Site 7: North Head
Site 8: North East Cove of Northern Bay
Temperature (º C)
April May June July Aug Sept Oct Nov
Site 1 6.6 14.1 19.8 21.5 23.7 19.6 16.4 5.3
Site 3 7.2 14.7 19.2 21.5 23.7 19.9 16.3 5.7
Site 6 7.8 15.7 19.3 22.2 23.5 20.0 16.6 6.0
Site 7 7.3 15.3 19.3 22.2 24.1 19.9 16.5 6.5
Site 8 8.2 15.6 19.1 22.5 23.6 20.0 16.6 6.1
Dissolved Oxygen (mg/l)
April May June July Aug Sept Oct Nov
Site 1 11.10 7.50 7.29 7.07 7.58 7.88 8.48 11.44
Site 3 10.97 8.48 7.23 7.77 7.60 8.09 8.37 11.11
Site 6 10.25 8.03 6.69 6.62 7.52 7.61 8.28 11.00
Site 7 9.75 8.27 6.06 8.14 9.53 7.29 7.53 10.75
Site 8 9.47 7.48 5.39 5.65 5.95 6.94 7.90 10.66
Salinity (ppt)
Site 1 April May June July Aug Sept Oct Nov
Site 3 5.5 13.5 8.7 8.2 6.8 5.7 5.0 14.4
Site 6 5.3 12.8 8.6 7.7 6.6 5.6 4.9 14.5
Site 7 4.7 11.2 7.5 6.7 5.2 4.3 3.8 13.6
Site 8 4.5 4.2 4.9 4.2 3.3 2.8 2.3 7.3
4.6 5.6 5.4 6.7 4.9 4.1 3.5 12.4
Secchi Disk
Depth (ft.)
April May June July Aug Sept Oct Nov
Site 1 3 2 4 3 4 4 5.5 4.5
Site 3 2.5 2 4 3.5 3 5 6 4
Site 6 3 1.5 2 2.5 2.25 2 3 3.3
Site 7 2.5 2.5 4 3 2 2.5 2.8 4.1
Site 8 2.5 2 2 2.5 1.6 1.5 3 2.2
Pond
Elevation at
Pole (ft.)
April May June July Aug Sept Oct Nov
Feet 5 2 3.5 3.3 3 2.2 2.6 1.8
Nitrate (NO3
ppb)
April May June July Aug Sept Oct Nov
Site 1 BRL BRL 10 10 10 BRL BRL
Site 3 BRL 10 <10 BRL 10 BRL BRL
Site 7 BRL BRL 130 BRL 10 BRL 10
Ammonia
(NH3 ppb)
April May June July Aug Sept Oct Nov
Site 1 50 150 280 130 90 120 100
Site 3 40 550 160 80 70 130 90
Site 7 40 90 110 130 60 100 50
Kjeldhal
Nitrogen
(TKN ppb)
April May June July Aug Sept Oct Nov
Site 1 BRL 1,190 560 1,050 700 770 910
Site 3 BRL 1,120 210 700 980 630 700
Site 7 BRL 2,800 210 770 2,660 1,400 1,470
Organic
Nitrogen
(TKN - NH3
= ON ppb)
April May June July Aug Sept Oct Nov
Site 1 BRL 1,040 280 920 610 650 810
Site 3 BRL 570 50 620 910 500 610
Site 7 BRL 2,710 100 640 2,600 1,300 1,420
Total
Nitrogen (TN
ppb)
April May June July Aug Sept Oct Nov
Site 1 <100 1,190 570 1,060 710 770 910
Site 3 <100 1,130 210 700 990 630 700
Site 7 <100 2,280 340 770 2,670 1,400 1,470
Total
Phosphorous
(TP ppb)
April May June July Aug Sept Oct Nov
Site 1 32 104 63 112 BRL 46 42
Site 3 70 135 80 87 99 37 41
Site 7 78 147 82 204 673 733 703
BRL = Below
Reportable
Limit
ND = Not Detected / Below
Detectable Limit
Appendix C Average Monthly Rainfall 2007 Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Inches 3.27 0.97 2.98 3.95 2.23 0.7 2.29 1.45 3.13 1.16 6.36 0.4 Total Rainfall: 28.89 " December Rainfall Incomplete