HomeMy WebLinkAboutHummock Pond Annual Report 2006_201401221138389484
Hummock Pond
Annual Report
2006
Prepared for:
Marine and Coastal Resource Department
34 Washington Street
Nantucket, MA 02554
Prepared by:
Keith L. Conant
Town Biologist
March 2007
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 and 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 ’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. Preliminary investigations have already begun
with help from Marine Department personnel. A more intensive study will begin in the
summer of 2007 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). 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 2006 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 2006
the main body of the pond stayed around 24ºC, or 75ºF (Appendix A). 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 Sites 7, and 8, just under 77ºF in July. 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. The lowest dissolved oxygen readings taken, coincide
with the highest temperature recordings taken in July and August (Appendix A). Periods
of hypoxia occurred at the bottom at Site 1 in July where 2.67 mg/l and 2.62 mg/l were
recorded at 9 and 11 feet. Anoxic conditions were also recorded during this month at
Sites 6, and 7. The lowest recorded reading was taken at Site 7, on the bottom at 0.06
mg/l. The month of August showed similar recordings, with low D.O. conditions
existing at Sites 6, 7, and 8. It is during these anoxic events that nutrients are released
from sediments on the bottom, further exacerbating enriched conditions. As a
coincidence a blue-green algae bloom was seen traveling down the connector from the
north head during the August sampling round. The algae bloom concentration increased
in the direction of the north head, from which it was emanating. With the onset of Fall,
D.O. conditions began to improve with declining temperatures. However there were
some low recordings at Sites 1, and 3 following the opening 10/25, but were primarily
related to salinity gradients. Site 7 also continued to show anoxic, and hypoxic
conditions in October (0.19 mg/l), and November (2.62 mg/l) on the bottom as a result of
the nutrient enriched conditions.
Figure 1: Average Temperature 2006
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 2006
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 2006 spring
opening occurred 4/24, and remained opened until 5/4, the fall opening occurred 10/25
and remained open until 10/29. 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 5). 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 (6 ppt) in April prior to the spring
pond opening. The pond increased in average salinity to 10ppt after the opening. There
were of course differences between the foot and the North head, prior to, and after the
opening (Appendix A). These differences were greatest (8.7 ppt) following the closure,
as the pond began to seek equilibrium with a well defined salt wedge. 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 quickened this year by the high amount of precipitation accumulated over the
summer. Signs of freshening occurred first at Site 7 in May, and then Site 8 in June, as
freshwater inputs from the northern watershed drive the freshening of the pond. The
lowest salinity reading taken on the pond was at Site 8 on the surface in June, at (0.4 ppt).
The average pond salinity was 2.5 ppt in October prior to the fall opening. When
the pond closed on 10/29, it closed on a high tide with a storm surge; after approximately
8 tidal exchanges. The result of this was an extremely high salinity throughout the pond.
Bottom measurements at the foot and the head were recorded at 27.9 ppt for Site 1, and
17.1 ppt for Site 7. Top to bottom differences were as much as 8 ppt (Site 7). Salinity in
the pond has not been to this level since the year 2000, where in May, Site 1 was
measured at 31.5 ppt at the bottom.
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 ’07 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 opening
several dead yellow perch were seen floating on the surface; the benthic community was
not sampled. Hopefully though, the openings will 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 2006
Average Salinity
0.0
5.0
10.0
15.0
20.0
25.0
30.0
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
considerable precipitation throughout the summer. As previously discussed rainfall
directly affects volume and salinity in the ponds. It also affects the amount of nutrients
that are carried in 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 2006
Average Monthly Rainfall
0
2
4
6
8
10
JanFebMarAprMayJunJulAugSept OctNovDecMonthInches Inches
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 nutrients
available in the water column. The disc measures 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 depth, bathymetry, and poor water quality, it has a relative
high abundance of submerged aquatic vegetation. Secchi disk depth recordings reflect
this condition. 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 ecosystem.
Secchi disk depth recordings were low, (2.5 ft average) for most of the sampling
period, indicating 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 one its high readings in June at 5 ft. This may have been the result of a shift
in phytoplankton communities as a result of the freshening of the pond due to high levels
of precipitation in and around that time period; 8.23” in June. A total 16.08” of rain was
recorded between the months of May to July, uncommonly high for this time period. The
lowest secchi disk recording, (1 ft.) was taken at Site 8 in July. The highest recording
was taken at Site1, and measured to 8ft. This was undoubtedly due to the high volume of
exchange with ocean water during the fall opening, which improved secchi disk depths at
all locations (with the exception of Site 8, due to pond weeds).
Figure 5: Secchi Disk Depth 2006
Secchi Disk Depth
0
2
4
6
8
10
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.
The study also showed that when the pole was at 4ft., the pond was approximately 8 ft.
above MSL. At 5 ft. the pond would be at a somewhat flooded condition, with a surface
area coverage of 267 acres.
When the pond was opened in April, it was just over 4ft. (Appendix B, and
Figure 6). The pond closed on a low tide, but was soon filled with fresh groundwater
from all the precipitation in May, June and July. As precipitation dropped off in August
and September so did elevation at the pole, approximately 3 ft. The pole elevation
combined with salinity also shows how the pond was emptied, and filled back to the same
elevation following the fall opening. This 3 ft. mark, that the pole was at in October and
November, puts the pond at approximately 6 ft. above mean sea level.
Figure 6: Pond Elevation at Pole 2006
Pond Elevation at Pole
0
1
2
3
4
5
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 has more of an effect toward the foot of the pond than
the head, because of the ponds shape, fresh water recharge, and the varying saline
conditions. Total nitrogen includes both organic and inorganic components. Ammonia
or NH3 was the only constituent in 2006 where the detectable limit was required to be
lowered during lab analysis in order to approximate actual levels occurring in Hummock
pond. 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.
Total nitrogen reached exceedingly high levels in July at Sites 1 and 3, where
2,000 ppb and 1,800 ppb TN were recorded from those sample sites respectively. Figure
7 shows an increasing trend for much of the summer, with a peak concentration of 2,220
ppb TN at Site 7 in August. During the months of July and August there were anoxic
dissolved oxygen levels recorded at Site 7. This undoubtedly led to a release of nutrients
from the sediments. Ammonia levels were also high in August for Site 7, (Appendix B),
this presence was also probably the result of the anoxic events. Total nitrogen was below
eutrophic conditions for the last three months sampled at Sites 1, and 3, and the last two
months at Site 7. The large exchange that occurred in the fall opening will be expected to
decrease nitrogen levels for the summer of 2007, as long as pond temperatures remain
cool, and anoxic events are avoided. If this is not the case then 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
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, and associated phytoplankton species; 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.
Phoshorous levels rising above 50 ppb indicate eutrophic conditions.
The majority of water samples taken at Hummock for the summer of 2006
indicate eutrophic conditions with respects to phosphorous. All samples taken at Site 3
are above the impaired level. Some are twice the eutrophic limit and two samples taken
in June, and September at Site 3 are three times that magnitude; showing 142 ppb and
156 ppb (Appendix B). Site 1, the area with the most saline conditions showed the
lowest average TP for 2006. However the initial readings at Sites 1 were high, with a
spike in August to 143 ppb. Coincidentally July and August exhibited periods of hypoxia
and anoxia at different locations in Hummock. This would result in a release of
phosphorous from bottom sediments. Indications of this can be seen in figure 8, from the
physical presence of the blue-green algae bloom witnessed in the north head, and its
connector in August. The TP sampled at Site 7 at that time was the highest recorded for
the 2006 sampling period, 262 ppb TP. Prior to and following the August sampling, TP
had dropped below a reportable limit at both Sites 3, and 7. It may be conjectured that at
these times, July and September, all the available TP in the system was being used up by
the phytoplankton community that had evolved from the freshening of the pond, and the
availability of TP. This would in turn help create the anoxic period in August, that
resulted in a massive release of Phosphorous from the sediments; which in turn created a
hyper-eutrophic state. TP values remained high for the last two months of the sampling
period, October and November; despite the opening of the pond, decreasing water
temperatures, and increasing dissolved oxygen in the water column.
Figure 8: Total Phosphorous 2006
Total Phosphorous TP
0
50
100
150
200
250
300
April May June July Aug Sept Oct Nov
Month Sampled(ppb)Site 1
Site 3
Site 7
Conclusions:
The summary of results from the 2006 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 destratify the north head of Hummock 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 currently
conducting some preliminary 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
2006
Physical and Chemical Data
Site 1: Foot of Pond
Site 3: Middle of Pond / Top of Main Body
Site 6: Northen Bay
Site 7: North Head
Site 8: North East Cove of Northern Bay
Temperature (º C)
Site 1 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 10.1 12.5 17.7 23.9 23.5 16.6 11.1 7.2
3 9.7 12.5 17.6 23.8 23.5 16.6 11.1 7.1
6 9.4 12.4 17.5 23.3 23.3 16.6 11.1 11.4
9 9.1 12.4 17.4 22.7 22.9 16.6 11.1 11.8
11 8.9 17.3 22.4 22.8 16.6 11.1
Site 3 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 10.3 12.5 18.1 24.5 23.6 16.9 11.5 8.2
3 10.2 12.5 18.1 24.5 23.6 17 11.5 8.2
6 9.6 12.4 18 24.4 23.3 17 11.5 8.2
7 9.5 17.9 24.3 23.3 17 11.6 11.5
Site 6 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 10.8 12.8 19.3 24.7 23.3 16.5 11.8 9.1
3 10.7 12.3 18.8 24.7 23.3 16.5 11.8 10.3
6 10.5 17.9 24.5 23.7 16.5 11.7 11.6
Site 7 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 10.6 12.9 19 24.8 23.7 17.8 12 8.1
3 10.5 12.8 18.9 24.6 23.5 17.8 12.1 10.6
6 10.3 12.5 18.7 24.6 23.2 17.8 12.1 10.4
9 9.7 12.3 17.7 23.2 23.1 17.8 12.1 10.3
12 9.3 12.3 17.5 19.8 22.3 18 12.3 10.7
13 9.1 17.4 18.5
Site 8 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 11.6 13.6 18.2 24.9 24.1 16.7 11.7 6.1
3 11.5 12.4 18.9 24.4 23.8 16.7 11.7 7.8
5 11.1 18.4 24.3 16.7
Dissolved Oxygen (mg/l)
Site 1 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 9.49 8.04 8.44 7.02 6.3 8.41 9.63 9.58
3 9.44 8.01 8.26 6.99 6.26 8.42 9.61 9.53
6 9.53 8.01 8.06 6.45 5.5 8.34 9.68 3.42
9 9.41 7.64 7.56 2.67 4.71 8.41 9.71 2.42
11 9.36 7.76 2.62 4.62 7.62 9.19
Site 3 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 9.54 8.31 8.34 6.83 8.16 8.65 9.71 9.16
3 9.53 8.29 8.3 6.75 8.1 8.54 9.59 9.14
6 9.22 8.12 8.29 6.62 6.03 8.55 9.64 9.09
7 9.21 8.01 5.99 5.84 7.74 9.54 2.65
Site 6 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 9.19 8.27 8.53 7.26 6.88 8.57 9.11 8.48
3 9.25 7.61 8.13 7.2 6.64 8.54 9.08 8.31
6 8.72 4.92 0.49 2.75 8.45 8.95 6.11
Site 7 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 9.86 8.56 9.15 8.98 7.6 8.88 9.59 10.81
3 9.84 8.59 9.06 8.97 5.39 8.77 9.49 8.96
6 9.74 7.82 9.28 8.94 5.24 8.73 9.5 7.52
9 9.36 6.65 7.48 3.79 4.57 8.78 9.48 7.25
12 7.91 4.36 3.93 0.09 0.14 5.58 0.19 2.62
13 7.69 3.67 0.06
Site 8 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 8.59 6.76 3.09 4.99 5.53 7.54 8.41 9.46
3 8.64 6.68 7.4 5.72 3.08 7.57 7.95 8.48
5 9.27 3.44 3.78 5.06
Salinity (ppt)
Site 1 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 6.7 15.5 8.5 5.8 4.4 3.8 3.1 23
3 6.7 15.5 8.5 5.8 4.4 3.8 3.1 22.8
6 6.7 15.5 8.5 5.8 4.4 3.8 3.1 27.6
9 6.7 15.5 8.5 5.9 4.4 3.8 3.1 27.9
11 6.7 8.5 5.9 4.4 3.8 3.1
Site 3 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 6.5 15.3 8.1 5.7 4.1 3.7 3 23
3 6.5 15.3 8.1 5.7 4.1 3.7 3 23
6 6.5 15.3 8.2 5.7 4.3 3.7 3 23
7 6.5 8.1 5.7 4.3 3.7 3 27
Site 6 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 5.7 12.2 3.8 4.8 3.3 2.7 2.3 20.7
3 5.7 15.6 5 4.8 3.3 2.7 2.3 22.1
6 6.2 7.8 4.8 4.1 2.7 2.3 24.5
Site 7 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 5.3 4.8 4.7 3.4 2.6 2.2 1.6 9
3 5.3 4.8 4.7 3.4 2.6 2.2 1.6 12.7
6 5.3 5.1 4.9 3.4 2.6 2.2 1.6 14.2
9 5.3 7.1 4.9 4.1 2.6 2.2 1.6 15.5
12 5.3 7.4 4.9 4.9 2.7 2.2 1.6 17.1
13 5.3 4.9 4.9
Site 8 4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
0 5.5 13.5 0.4 2.2 3 2.4 2.2 13.5
3 5.5 15.1 5 4 3.5 2.4 2.2 17.2
5 5.5 5.9 4.6 2.5
Secchi Disk Depth
(ft.)
4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
Site 1 2.5 2.5 3 2 4 2 3 8
Site 3 2.5 2.5 2.5 3 3 2 3.5 6
Site 6 3.1 2.1 2.5 3 2 1.75 3 4.5
Site 7 2.3 2 5 4 2 1.5 3.5 5
Site 8 3.3 2 2.5 1 3 1.1 3 3
Pond Elevation at Pole (ft.)
4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
Feet 4.1 1.9 4 4 3.5 3.25 3 3
Nitrate (NO3 ppb)
4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
Site 1 20 BRL 20 BRL BRL 60 10 <10
Site 3 <10 BRL BRL 10 BRL BRL BRL <10
Site 7 20 BRL 230 10 120 BRL 10 <10
Ammonia (NH3 ppb)
4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
Site 1 65 23 ND ND 170 100 90 70
Site 3 44 48 ND ND 140 130 70 70
Site 7 47 47 20 ND 640 150 100 170
Kjeldhal Nitrogen (TKN ppb)
4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
Site 1 420 630 840 2,000 980 140 BRL <100
Site 3 630 560 630 1,800 950 200 BRL <100
Site 7 490 630 770 1,000 2,100 2,040 450 <100
Total Nitrogen (TN
ppb)
4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
Site 1 440 630 860 2,000 960 200 <100 <100
Site 3 630 560 630 1,800 950 200 <100 <100
Site 7 510 630 1,000 1,000 2,220 2,040 460 <100
Total Phosphorous (TP ppb)
4/12/2006 5/11/2006 6/13/2006 7/11/2006 8/22/2006 9/12/2006 10/24/2006 11/6/2006
Site 1 103 83 BRL BRL 143 BRL 86 87
Site 3 105 76 142 108 115 156 87 75
Site 7 108 126 114 BRL 262 BRL 156 107
BRL = Below Reportable Limit
ND = Not Detected / Below Detectable Limit
Appendix B
Hummock Pond 2006
Average Physical and Chemical Data with Charts
Site 1: Foot of
Pond
Site 3: Middle of Pond / Top of Main
Body
Site 6: Nothern
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 9.4 12.5 17.5 23.2 23.2 16.6 11.1 9.4
Site 3 9.9 12.5 18.0 24.4 23.5 17.0 11.5 9.0
Site 6 10.7 12.6 18.7 24.6 23.4 16.5 11.8 10.3
Site 7 9.9 12.6 18.2 22.6 23.2 17.8 12.1 10.0
Site 8 11.4 13.0 18.5 24.5 24.0 16.7 11.7 7.0
Dissolved Oxygen (mg/l)
April May June July Aug Sept Oct Nov
Site 1 9.45 7.93 8.02 5.15 5.48 8.24 9.56 6.24
Site 3 9.38 8.24 8.24 6.55 7.03 8.37 9.62 7.51
Site 6 9.05 7.94 7.19 4.98 5.42 8.52 9.05 7.63
Site 7 9.07 7.20 7.10 5.14 4.59 8.15 7.65 7.43
Site 8 8.83 6.72 4.64 4.83 4.31 6.72 8.18 8.97
Salinity (ppt)
April May June July Aug Sept Oct Nov
Site 1 6.7 15.5 8.5 5.8 4.4 3.8 3.1 25.3
Site 3 6.5 15.3 8.1 5.7 4.2 3.7 3.0 24.0
Site 6 5.9 13.9 5.5 4.8 3.6 2.7 2.3 22.4
Site 7 5.3 5.8 4.8 4.0 2.6 2.2 1.6 13.7
Site 8 5.5 14.3 3.8 3.6 3.3 2.4 2.2 15.4
Secchi Disk Depth (ft.)
April May June July Aug Sept Oct Nov
Site 1 2.5 2.5 3 2 4 2 3 8
Site 3 2.5 2.5 2.5 3 3 2 3.5 6
Site 6 3.1 2.1 2.5 3 2 1.75 3 4.5
Site 7 2.3 2 5 4 2 1.5 3.5 5
Site 8 3.3 2 2.5 1 3 1.1 3 3
Pond Elevation at Pole (ft.)
April May June July Aug Sept Oct Nov
Feet 4.1 1.9 4 4 3.5 3.25 3 3
Nitrate (NO3 ppb)
April May June July Aug Sept Oct Nov
Site 1 20 BRL 20 BRL BRL 60 10 <10
Site 3 <10 BRL BRL 10 BRL BRL BRL <10
Site 7 20 BRL 230 10 120 BRL 10 <10
Ammonia (NH3
ppb)
April May June July Aug Sept Oct Nov
Site 1 65 23 ND ND 170 100 90 70
Site 3 44 48 ND ND 140 130 70 70
Site 7 47 47 20 ND 640 150 100 170
Kjeldhal Nitrogen (TKN ppb)
April May June July Aug Sept Oct Nov
Site 1 420 630 840 2,000 980 140 BRL <100
Site 3 630 560 630 1,800 950 200 BRL <100
Site 7 490 630 770 1,000 2,100 2,040 450 <100
Total Nitrogen (TN ppb)
April May June July Aug Sept Oct Nov
Site 1 440 630 860 2,000 960 200 <100 <100
Site 3 630 560 630 1,800 950 200 <100 <100
Site 7 510 630 1,000 1,000 2,220 2,040 460 <100
Total Phosphorous (TP ppb)
April May June July Aug Sept Oct Nov
Site 1 103 83 BRL BRL 143 BRL 86 87
Site 3 105 76 142 108 115 156 87 75
Site 7 108 126 114 BRL 262 BRL 156 107
BRL = Below Reportable Limit
ND = Not Detected / Below Detectable Limit
Appendix C
Average Monthly Rainfall
2006
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
Inches 4.86 1.98 0.85 2.13 4.5 8.23 4.07 3.05 0.76 2.6 4.19 3.32
Total Rainfall: 40.54 "