2015 DES` Water Quality Assessment of Spofford Lake

Volunteer Lake Assessment Program Individual Lake Reports
SPOFFORD LAKE, CHESTERFIELD, NH
MORPHOMETRIC DATA
TROPHIC CLASSIFICATION
Watershed Area (Ac.): 2,880
Surface Area (Ac.):
707
Shore Length (m):
8,400
Max. Depth (m): 19.5
Mean Depth (m): 9.1
Volume (m³):
26,020,500
Flushing Rate (yr¹) 0.2
P Retention Coef: 0.82
Elevation (ft):
716
Year
KNOWN EXOTIC SPECIES
Trophic class
1988
OLIGOTROPHIC
1995
OLIGOTROPHIC
The Waterbody Report Card tables are generated from the DRAFT 2014 305(b) report on the status of N.H. waters, and are based on data collected from 20042013. Detailed waterbody assessment and report card information can be found at www.des.nh.gov/organizations/divisions/water/wmb/swqa/index.htm
Designated Use
Parameter
Category
Comments
Aquatic Life
Phosphorus (Total)
Good
The calculated median is from 5 or more samples and is < indicator and > 1/2 indicator and the chlorophyll a
indicator is okay.
pH
Slightly Bad
>10% of samples exceed criteria by a small margin (minimum of 2 exceedances).
Oxygen, Dissolved
Bad
There are >10% of samples (minimum of 2), exceeding criteria with one or more samples considered large
exceedance.
Primary Contact Recreation
Dissolved oxygen satura Slightly Bad
There are >10% of samples (minimum of 2), exceeding criteria.
Chlorophyll-a
Good
The calculated median is from 5 or more samples and is < indicator and > 1/2 indicator.
Escherichia coli
Good
There are geometric means and all geometric means are < geometric mean criteria; and there has been a single
sample exceedance.
Chlorophyll-a
Very Good
There are a total of at least 10 samples with 0 exceedances of indicator.
BEACH PRIMARY CONTACT ASSESSMENT STATUS
SPOFFORD LAKE - ROADS END FARM BEACH
Escherichia coli Good
There are geometric means and all geometric means are < geometric mean criteria; and there has
been a single sample exceedance.
SPOFFORD LAKE - CAMP SPOFFORD BEACH
Escherichia coli Good
There are geometric means and all geometric means are < geometric mean criteria; and there has
been a single sample exceedance.
SPOFFORD LAKE - WARES GROVE TOWN
BEACH
Escherichia coli Good
There are geometric means and all geometric means are < geometric mean criteria; and there has
been a single sample exceedance.
SPOFFORD LAKE - N SHORE RD TOWN BEACH
Escherichia coli Good
There are geometric means and all geometric means are < geometric mean criteria; and there has
been a single sample exceedance.
SPOFFORD LAKE - ACCESS RD TOWN BEACH
Escherichia coli No Data
No data for this parameter.
WATERSHED LAND USE SUMMARY
Fry, J., Xian, G., Jin, S., Dewitz, J., Homer, C., Yang, L., Barnes, C., Herold, N., and Wickham, J., 2011. Completion of the 2006 National Land Cover Database
for the Conterminous United States, PERS, Vol. 77(9):858-864. For larger image contact NHDES.
Land Cover Category
Land Cover Category
% Cover
Land Cover Category
% Cover
Open Water
29.9
Barren Land
0.12
Grassland/Herbaceous
0.13
Developed-Open Space
5.92
2.06
Deciduous Forest
23.2
23.48
Pasture Hay
3.44
0
Developed-Low Intensity
Developed-Medium Intensity
Developed-High Intensity
% Cover
0.92
Evergreen Forest
Mixed Forest
0.05
Shrub-Scrub
9.89
Cultivated Crops
Woody Wetlands
0.13
Emergent Wetlands
0.71
0.05
Volunteer Lake Assessment Program Individual Lake reports
Spofford Lake, Chesterfield
5 Data Summary
Recommended Actions: I -lake ate ualit is ge e all good a d ep ese tai e of Oligot ophi , o high ualit
ate , o diio s. Ho e e , Ca p Spofo d I let o i ues to
e hi it ele ated phospho us a d E. oli le els, pa i ula l ate sig ii a t sto e e ts. Co du t a st ea
alk a d a ket sa pli g to help dete i e the sou e s of
ele ated polluta ts. Pote ial sou es ould i lude fe ilize s, ag i ultu e a d sepi s ste s. Co ta t the VLAP Coo di ato fo assista e. Co du i it a d hlo ide le els
e ai ele ated i se e al t i uta ies due to oad salt appli aio s o
ajo oad a s i the ate shed. Sto ate u of f o sig ii a t sto e e ts i pa ts t i uta ies a d
the lake. Ide if a eas he e sto
ate a age e t p oje ts ould e i ple e ted to edu e the egai e i pa ts. Joi Soak up the Rai NH to sta t ide if i g a d
i ple e i g sto
ate est p a i es. Visit htp://soak h.o g/ fo o e i fo aio . Keep up the g eat o k!
Observations Refer to Ta le and , and Histori al Deep Spot Data Graphi s)
Chlorophyll-a: Chlo oph ll le els e ai ed sta le a d lo f o Ju e th ough August. The
a e age hlo oph ll le el
e ai ed sta le ith
a d as u h less tha the state edia . Histo i al t e d a al sis i di ates elai el sta le
hlo oph ll ith ode ate a ia ilit et ee ea s.
Conductivity/Chloride: Deep spot, Outlet, Shield I let, a d Wa es G o e I let o du i it a d hlo ide le els e e slightl
ele ated a d g eate tha the state edia s. Histo i al t e d a al sis i di ates sig ii a tl i easi g o se i g epili ei
uppe ate la e o du i it si e o ito i g ega . Ca p Spofo d I let, Cla kdale Pipe a d Sea a s I let o du i it a d
hlo ide le els e e g eatl ele ated a d hlo ide le els i Sea a s I let app oa hed the state h o i hlo ide sta da d i Jul .
E. coli: All ea hes, e ept fo Cla kdale a d Isla d No th West, E. oli le els e e less tha the state sta da d fo pu li ea hes
ts/
L o ea h sa pli g e e t. Cla kdale Bea h a d Isla d No th West E. oli le els e eeded the state sta da d fo
pu li ea hes i August. Ca p Spofo d I let, Cla kdale Pipe, Outlet, Sea a s I let, a d Wa es G o e I let E. oli le els e e
ele ated i August follo i g a sig ii a t sto e e t, ut e e ot g eate tha the state sta da d of
ts/
L fo
su fa e ate s.
Total Phosphorus: Epili ei phospho us as slightl ele ated i Ju e a d the de eased to e lo le els i Jul a d
August. A e age epili ei phospho us i eased f o
a d as less tha the state edia . Histo i al t e d a al sis
i di ates highl a ia le epili ei phospho us si e o ito i g ega . Metali ei
iddle ate la e a d H poli ei
lo e ate la e phospho us le els e ai ed sta le a d ithi lo to a e age a ges. Ca p Spofo d I let phospho us le els
e e g eatl ele ated i Ju e a d August follo i g sig ii a t sto e e ts a d phospho us le els ha e sig ii a tl i eased
o se ed i the I let si e o ito i g ega a d pa i ula l si e
. Cla kdale Pipe, Sea a s, Shield, a d Wa es G o e
I lets’ phospho us le els e e ithi lo to a e age a ges fo those staio s. Outlet phospho us le els e e g eatl ele ated i
Jul a d August a d la otes i di ate ode ate le els of o ga i ate ial i the sa ples.
Transparency: T a spa e
lu tuated slightl f o Ju e to August et e ai ed high good . A e age t a spa e
i p o ed
fo
a d as u h ete tha the state edia . Histo i al t e d a al sis i di ates sta le t a spa e
si e o ito i g
ega .
Turbidity: Epili ei tu idit as slightl ele ated i Ju e a d Metali ei tu idit as slightl ele ated i August follo i g
sig ii a t sto e e ts. Cla kdale Pipe tu idit as ele ated o ea h sa pli g e e t due to highl olo ed ate a d i o
a te ia p e ipitate. Ca p Spofo d a d Shield I let tu idiies e e slightl ele ated i Jul . Outlet a d Sea a s I let tu idiies
e e slightl ele ated i August.
pH: Epili ei pH as ithi the desi a le a ge . - . u its ho e e histo i al t e d a al sis i di ates sig ii a tl
de easi g o se i g epili ei pH si e o ito i g ega . Metali ei , H poli ei a d t i uta pH le els lu tuated
elo the desi a le a ge o o asio .
Staio Na e
Epili io
Metali io
H poli io
Ca p Spofo d I let
Cla kdale Bea h
Cla kdale Pipe
Outlet
Sea a s I let
Shield I let
Wa es G o e I let
Ta le .
A e age Wate Qualit Data fo SPOFFORD LAKE
Alk. Chlo -a Chlo ide Co d. E. Coli Total P
T a s.
Tu .
g/l ug/l
g/l uS/
#/
l ug/l
tu
NVS VS
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pH
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Staio Na e
Ta le .
A e age
Bea h Ba te ia Results
E. Coli
#/
l
B + K Bea h
Boat Lau h
Ca p Spofo d Bea h
Cla kdale Bea h
Fa il Re Bea h
Isla d No th East
Isla d No th West
Isla d South East
Isla d South West
No th Sho e Bea h
Wa es G o e Bea h
NH Media Values: Media alues fo spe ii
pa a ete s ge e ated f o histo i lake o ito i g data.
Alkali it : .
g/L
Chloroph ll-a: .
g/
Co du ivit : . uS/
Chloride:
g/L
Total Phosphorus: ug/L
Tra spare : .
pH: .
NH Water Qualit Sta dards: Nu e i ite ia
fo spe ii pa a ete s. Results e eedi g
ite ia a e o side ed a ate ualit iolaio .
Chloride: >
g/L h o i
E. oli: >
ts/
L – pu li ea h
E. oli: >
ts/
L – su fa e ate s
Tur idit : > NTU a o e atu al le el
pH: et ee . - . u less atu all o u i g
.
.
.
.
.
Historical Water Quality Trend Analysis
Para eter
Co du i it
pH epili io
Tre d
Wo se i g
Wo se i g
This epo t as ge e ated
E pla aio
Data sig ii a tl i easi g.
Data sig ii a tl de easi g.
the NH DES Volu tee Lake Assess e t P og a
Para eter
Chlo oph ll-a
T a spa e
Phospho us epili
VLAP . Fo
o e i fo
io
aio
Tre
Sta
Sta
Sta
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le
le
le
o ta t VLAP at
E
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T
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pla
e d
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ot sig ii a t; data ode atel a ia le.
ot sig ii a t; data sho lo a ia ilit .
ot sig ii a t; data highl a ia le.
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o sa a.stei e @des. h.go