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Background lakes and comparisons in Nova Scotia, Guidelines

Soil & Water Conservation Society of Metro Halifax (SWCSMH)

Updated: January 03, 2016                      Lake Data Archives

(Note: The following is mostly from older Government reports for comparison purposes only. It is impractical to publish all of our extensive archives of later chemical as well as biological data on the internet. It exists with us in computer based sheets/programs, printed reports, and some are still in handwritten notebooks. When volunteer time (and funds) allow us, we will either develop computer sheets/programs and/or publish in printed reports in which case we will make them publicly available as before. For further info see our Studies/Reports, and our web pages of select lakes)


Contents:

(also cf., Lake morphology)



Introduction

This web page has been prepared with historical data on several variables, both for overall provincial and Halifax Metro averages as well as for pristine and relatively undisturbed lakes. With some exceptions, these may be used for comparing any field data. The relevant guidelines from Environment Canada, 2004, the CCME (Canadian Ministers of the Environment), OME (Ontario Ministry of the Environment), Health and Welfare Canada, and the NRCC (National Research Council of Canada), have also been included.



Parameters

Surface Area (ha)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
85 SD 192175 Halifax Co. lakesAlexander et al, 1986
89 SD 279781 Nova Scotia lakesAlexander et al, 1986


Maximum Depth (m)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
10.6 SD 8.4175 Halifax Co. lakesAlexander et al, 1986
8.2 SD 6.8772 Nova Scotia lakesAlexander et al, 1986


Mean Depth (m)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
3.1 SD 2.4118 Halifax Co. lakesAlexander et al, 1986
2.8 SD 2.1660 Nova Scotia lakesAlexander et al, 1986


Total Phosphorus, TP (as Phosphorus g/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
mean=2.7
   (<1 - 5)
22 pristine Halifax Co. clear-water lakes (Dec. 1984)Data from John Underwood (pers. comm. Feb. 1994); Lakes Jack, Bayers, Susies, Bell, Paces, Kearney, Grand [Preston], Eagle, Long [Preston], Horseshoe, Uniacke, Cochran, Lewis [Kearney watershed], McQuade, Anderson, Spruce Hill, Ragged, Cooper, Otter, Land of Laziness, Coxs, and Long
4Clear-water Pockwock Lake (1991-92; 4 events; TSI[TP]=24, TSI[Cha]=24])Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
5Clear-water Bell Lake (1991-92; 30 events; TSI[TP]=27, TSI[Cha]=34)Clear-water, urban lake in Dartmouth, Mandell (1994)
6Clear-water Bell Lake (1990; 3 events; TSI[TP]=30, TSI[Cha]=26)Clear-water, urban lake in Dartmouth, SWCS (1991)
2Clear-water Chocolate Lake (1991-92; 4 events; TSI[TP]=14, TSI[Cha]=11])Clear-water, urban lake in Halifax, Mandell (1994)
3.8Clear-water Beaverskin Lake (near surf. yearly means; TSI[TP]=23, TSI[Cha]=34])Undisturbed clear-water lake in a National Park, Kerekes (1975)
6.6, 6.0Clear-water Beaverskin Lake (May-April 1979-80: TSI[TP]=31, TSI[Cha]=32]; May-April 1980-81: TSI[TP]=30, TSI[Cha]=31]; wtd. means)Undisturbed clear-water lake in a National Park, Beauchamp and Kerekes (1989)
mean= 7.1
   (3- 17)
14 Halifax County Coloured-water lakes (Dec. 1984)Data from John Underwood (pers, comm. Feb. 1994), Lakes Spectacle, Howe, O'Brien, Kidston, Hubley's Big, Peters [Eastern Shore], Big Bridge Bog Pond, Welsh, Long Canal, Purcell's Pond, Duncan's Pond, Fink Pond, Black, and Silver
9.1Coloured-water Kejimkujik Lake (near surf. yearly means)Undisturbed, colored-water lake in a National Park, Kerekes (1975)
10.4, 10.4Coloured-water Kejimkujik Lake (May-April 1979-80, May-April 1980-81, wtd. means)Undisturbed, colored-water lake in a National Park, Beauchamp and Kerekes (1989)
5 to 1017 Keji Park lakesKerekes. 1975




Environment Canada, 2004: Canadian Guidance Framework
< 4Ultra-oligotrophicAlmost nil impairment of multi-purpose use of lake
4-10Oligo-mesotrophicLittle impairment of multi-purpose use of lake
10-35Meso-eutrophicVariable impairment of multi-purpose use of lake
35-100EutrophicGreat impairment of multi-purpose use of lake
> 100HypereutrophicExtreme impairment of multi-purpose use of lake




OECD Management Model: There is no possibility of defining strict boundary values between trophic categories. This model incorporates the class midpoints for mean TP and mean Ch-a
mean < 2.5Ultra-oligotrophicAlmost nil impairment of multi-purpose use of lake
mean = 2.5-8OligotrophicLittle impairment of multi-purpose use of lake
mean = 8-25MesotrophicVariable impairment of multi-purpose use of lake
mean= 25-80EutrophicGreat impairment of multi-purpose use of lake
mean > 80HypertrophicExtreme impairment of multi-purpose use of lake


TP (mg/l) in sediments
Lake Means & GuidelinesLake & SpecificsReferences & Notes
1.2Natural lakes of Nova ScotiaUnderwood and Josselyn, 1979


PO4-P (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.001 SD 0.001234 N.S. lakesUnderwood et al, 1986


Mean Chlorophyll-a (g/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.53Clear-water Pockwock Lake (1991-92; 4 events; TSI[TP]=24, TSI[Cha]=24)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
1.41Clear-water Bell Lake (1991-92; 30 events; TSI[TP]=27, TSI[Cha]=34)Clear-water, urban lake in Dartmouth, Mandell (1994)
0.6Clear-water Bell Lake (1990; 3 events; TSI[TP]=30, TSI[Cha]=26)Clear-water, urban lake in Dartmouth, SWCS (1991)
0.14Clear-water Chocolate Lake (1991-92; 4 events; TSI[TP]=14, TSI[Cha]=11])Clear-water, urban lake in Halifax, Mandell (1994)
1.4Clear-water Beaverskin Lake (near surf. yearly means; TSI[TP]=23, TSI[Cha]=34])Undisturbed clear-water lake in a National Park, Kerekes (1975)
1.20, 1.03Clear-water Beaverskin Lake (May-April 1979-80: TSI[TP]=31, TSI[Cha]=32; May-April 1980-81: TSI[TP]=30, TSI[Cha]=31)Undisturbed, clear-water lake in a National Park, Beauchamp and Kerekes (1989)
2.1Coloured-water Kejimkujik Lake (near surf. yearly means)Undisturbed, colored-water lake in a National Park, Kerekes (1975)
1.16, 0.93Coloured-water Kejimkujik Lake (May-April 1979-80, May-April 1980-81, wtd. means)Undisturbed, colored-water lake in a National Park, Beauchamp and Kerekes (1989)
1.8 (1 to 3)17 Keji Park lakesKerekes, 1975
1.35 Terra Nova Park lakes, NFLDKerekes, 1975
3Lakes in the Canadian Shield in NW OntarioKerekes, 1975




Environment Canada, 2004: Canadian Guidance Framework
< 1Ultra-oligotrophicAlmost nil impairment of multi-purpose use of lake
< 2.5Oligo-mesotrophicLittle impairment of multi-purpose use of lake
2.5-8Meso-eutrophicVariable impairment of multi-purpose use of lake
8-25EutrophicGreat impairment of multi-purpose use of lake
> 25HypereutrophicExtreme impairment of multi-purpose use of lake




OECD Management Model: There is no possibility of defining strict boundary values between trophic categories. This model incorporates the class midpoints for mean TP and mean Ch-a
mean < 0.7Ultra-oligotrophicAlmost nil impairment of multi-purpose use of lake
mean = 0.7-2.1OligotrophicLittle impairment of multi-purpose use of lake
mean = 2.1-6.25MesotrophicVariable impairment of multi-purpose use of lake
mean= 6.25-19.2EutrophicGreat impairment of multi-purpose use of lake
mean > 19.2HypertrophicExtreme impairment of multi-purpose use of lake


Maximum Chlorophyll-a (g/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.73Clear-water Pockwock Lake (1991-92; 4 events; TSI[TP]=24, TSI[Cha]=24)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
3.33Clear-water Bell Lake (1991-92; 30 events; TSI[TP]=27; TSI[Cha]=34)Clear-water, urban lake in Dartmouth, Mandell (1994)
0.74Clear-water Bell Lake (1990; 3 events; TSI[TP]=30, TSI[Cha]=26)Clear-water, urban lake in Dartmouth, SWCS (1991)
0.23Clear-water Chocolate Lake (1991-92; 4 events; TSI[TP]=14, TSI[Cha]=11])Clear-water, urban lake in Halifax, Mandell (1994)
3.27, 2.24Beaverskin Lake (May-April 1979-80: TSI[TP]=31, TSI[Cha]=32; May-April 1980-81: TSI[TP]=30, TSI[Cha]=31)Undisturbed, clear-water lake in a National Park, Beauchamp and Kerekes (1989)
2.80, 1.92Coloured-water Kejimkujik Lake (May-April 1979-80, May-April 1980-81)Undisturbed, colored-water lake in a National Park, Beauchamp and Kerekes (1989)
Environment Canada, 2004: Canadian Guidance Framework
< 2.5Ultra-oligotrophicAlmost nil impairment of multi-purpose use of lake
< 8Oligo-mesotrophicLittle impairment of multi-purpose use of lake
8-25Meso-eutrophicVariable impairment of multi-purpose use of lake
25-75EutrophicGreat impairment of multi-purpose use of lake
> 75HypereutrophicExtreme impairment of multi-purpose use of lake





Total Nitrogen, TN (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.19 SD 0.0937 pristine Halifax Co. lakes (Dec. 1984)John Underwood (pers. comm.), Jan. 1994
0.09Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
0.06Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth. Mandell (1994)
0.2Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
0.145, 0.152Beaverskin Lake (May-April 1979-80, May-April 1980-81, wtd. means)Undisturbed, clear-water lake in a National Park, Beauchamp and Kerekes (1989)
0.17, 0.17Coloured-water Kejimkujik Lake (May-April 1979-80, May-April 1980-81, wtd. means)Undisturbed, colored-water lake in a National Park, Beauchamp and Kerekes (1989)
≤0.3Oligotrophic systemsUnderwood & Josselyn, 1979


Nitrate-N (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.02 SD 0.0337 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.) Jan, 1994
<0.19Susies Lake (1980-83)Undisturbed lake in Halifax Metro, Kerekes et al, 1986
10.0 as NDrinking Water- Maximum Acceptable ConcentrationCCME- Where both nitrate and nitrite are present the total nitrate- plus nitrite-nitrogen should not exceed 10


Nitrite-N (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.06Freshwater Aquatic LifeCCME guidelines
1.0 as NDrinking Water- Maximum Acceptable ConcentrationCCME- Where both nitrate and nitrite are present the total nitrate- plus nitrite-nitrogen should not exceed 10


Ammonia, NH4-N (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.007 SD 0.01937 pristine Halifax Co. lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994


Clarity (as Secchi disk depth in m)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
2.9N.S. AverageUnderwood & Josselyn, 1979
Minimum visibility at 1.2Recreational Water QualityCCME guidelines
Environment Canada, 2004: Canadian Guidance Framework
mean > 12
min. > 6
Ultra-oligotrophicAlmost nil impairment of multi-purpose use of lake
mean > 6
min. > 3
Oligo-mesotrophicLittle impairment of multi-purpose use of lake
mean = 6-3
min. = 3-1.5
Meso-eutrophicVariable impairment of multi-purpose use of lake
mean= 3-1.5
min. = 1.5-0.7
EutrophicGreat impairment of multi-purpose use of lake
mean < 1.5
min. < 0.7
HypereutrophicExtreme impairment of multi-purpose use of lake





Turbidity
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.92 SD 0.45 NTU37 pristine Halifax Co. lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994
1.05 SD 0.60 NTU234 N.S. lakesUnderwood et al, 1986
1Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
1Clear-water Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth, Mandell (1994)
0Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
5.0 NTU maximum increaseRecreational Water QualityCCME guidelines- Maximum allowable increase over natural turbidity when turbidity is low (<50 NTU)


TSS (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
3Average background conc. of N.S. lakesHinch & Underwood, 1985 (SS is the component of total residue retained by a 0.45 m filter and may consist of clay, silt, finely divided organics and inorganics, planktonic and microscopic organisms)
Maximum increase of 10.0Freshwater Aquatic LifeCCME guidelines- when background suspended solids ≤100.0
Maximum increase of 10% above backgroundFreshwater Aquatic LifeCCME guidelines- when background suspended solids >100.0


TDS (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
<30Natural background levels as a result of land drainage from natural sources such as weathering of rock, `waters in contact with granite`, siliceous sand, well-baked soil, or other relatively soluble materialHinch & Underwood, 1985 (TDS is the component of total residue that passes through a 0.45 m filter and refers primarily to inorganic salts and organic matter dissolved in water. Principal ions that contribute to TDS include: CO3, HCO3, Cl, SO4, NO3, Na, K, Ca, and Mg)
20
(12.45-86.14)
Average for pristine N.S. lakesHinch & Underwood, 1985
500Maximum Canadian objective drinking water standardHinch & Underwood, 1985


Colour
Lake Means & GuidelinesLake & SpecificsReferences & Notes
45 SD 48 TCU37 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan. 1994 (True color [TCU] results from dissolved substances in solution. One source, the humic substances [resulting from decay or aqueous extraction of natural vegetation] are of environmental significance since they tend to absorb a variety of organic substances as well as bind aluminum, many of which have toxic properties. Apparent color [Hazen U] results from suspended or colloidal matter [Health & Welfare Canada, 1980 per Hinch & Underwood, 1985])
5Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
5Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
2Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth. Mandell (1994)
4Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
44.5 SD 54.6 TCU234 N.S. lakesUnderwood et al, 1986
15 TCUDrinking Water- Maximum Acceptable ConcentrationCCME guidelines


TOC (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
8 (0.7 - 20)Pristine N.S. lakesHinch & Underwood, 1985 (TOC= suspended + dissolved organic constituents. High TOC values are commonly due to humic substances. Although not in itself a hazard, organic material may provide precursors of potentially harmful contaminants since humic acids tend to firmly adsorb or complex organic and inorganic pollutants and metals)


DOC (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
6.5 SD 6.437 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm. Jan, 1994)
2.7Susies Lake (Dec, 1985)Undisturbed lake in Halifax Metro. Urban et al, 1990
1.8Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
0.3Clear-water Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth, Mandell (1994)
0.45Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
5.73 SD 3.57234 N.S. lakesUnderwood et al, 1986
5.0Drinking WaterOME- Aesthetic Objective


Conductivity (S/cm)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
62.5 SD 32.037 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994. (Conductivity is the ability of a substance to conduct an electric current [per Hinch & Underwood, 1985])
45.6Susies Lake (Dec. 1985)Undisturbed lake in Halifax Metro. Urban et al, 1990
58.0 SD 74.8159 Halifax County lakesAlexander et al, 1986
33Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
49Clear-water Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth, Mandell (1994)
500Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
69.5 SD 493.0638 N.S. lakesAlexander et al, 1986
46.9 SD 23.8234 N.S. lakesUnderwood et al, 1986
<5Distilled water 
20 to 40Keji Park lakesTordon (Environment Canada)
70 to 90Halifax City tapwaterMcCarthy
30,000 +Seawater 


pH
Lake Means & GuidelinesLake & SpecificsReferences & Notes
4.9 SD 0.5637 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994
4.8 (calculated from eq/l)Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
5.32Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
5.67Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth. Mandell (1994)
5.21Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
5.7 SD 0.57234 N.S. lakesUnderwood et al, 1986
6.2 SD 0.6167 Halifax County lakesAlexander et al, 1986
6.2 SD 0.8730 N.S. lakesAlexander et al, 1986
5.0 to 9.0Recreational Water QualityCCME guidelines
6.5 to 9.0Freshwater Aquatic LifeCCME guidelines
6.5 to 8.5Drinking Water- Maximum Acceptable ConcentrationCCME guidelines


SO4 (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
5.9 SD 2.237 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994
4.79 (calculated from eq/l)Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
6Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
9.6Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth. Mandell (1984)
39Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
500Drinking Water- Maximum Acceptable ConcentrationCCME guidelines


Alkalinity (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.19 SD 0.3837 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994 (Alk. is the capacity of a solution to neutralize acid to a designated pH [per Hinch & Underwood, 1985])
0Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
0.09Clear-water Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth, Mandell (1994)
0Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
No decrease >25%Water Quality ObjectivesOME- should not be decreased by more than 25% of the natural concentration


Hardness as CaCO3 (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
80-100Acceptable balance between corrosion and incrustrationHinch & Underwood, 1985 (Hardness is a traditional measure of the capacity of water to react with soap. In freshwaters, the principal hardness-causing ions are Ca and Mg neither of which are considered concerns to health)
0-60Soft waterHealth & Welfare Canada, 1980 (per Hinch & Underwood, 1985)
60-120Medium hard WaterHealth & Welfare Canada, 1980 (per Hinch & Underwood, 1985)
120-180Hard waterHealth & Welfare Canada, 1980 (per Hinch & Underwood, 1985)
180 and aboveVery hard waterHealth & Welfare Canada, 1980 (per Hinch & Underwood, 1985)
7.1 SD 4.137 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994


Cl (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
10.3 SD 6.737 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994 (At 250 mg/l, salty taste may occur when the cation is Na. A high Cl content is known to harm metallic pipes as well as agricultural plants. Environmentally, Cl is a useful indicator of the effectiveness of lake mixing and dilution [per Hinch & Underwood, 1985])
4.08 (calculated from eq/l)Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
6.2Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
9Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth. Mandell (1994)
148Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
250Drinking Water- Maximum Acceptable ConcentrationCCME


Na (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
6.3 SD 4.137 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994
3.6 (calculated from eq/l)Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
3.8Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
4.9Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth. Mandell (1994)
88Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)


K (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.41 SD 0.1537 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994
0.14 (calculated from eq/l)Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
0.39Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
0.73Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth. Mandell (1994)
4.5Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)


Ca (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
1.6 SD 0.9537 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994
0.88 (calculated from eq/l)Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
1.4Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
2.6Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth.Mandell (1994)
13Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)


Mg (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.78 SD 0.4137 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994
0.44 (calculated from eq/l)Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
1Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
1Bell Lake (1991-92; 30 events)Relatively undisturbed, clear-water, urban lake in Dartmouth. Mandell (1994)
2Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)


Fe (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.073 (calculated from eq/l)Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
0.06Clear-water Pockwock Lake (1991-92; 4 events)Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
0.04Clear-water Bell Lake (1991-92; 30 events)Clear-water, urban lake in Dartmouth, Mandell (1994)
0.1Clear-water Chocolate Lake (1991-92; 4 events)Clear-water, urban lake in Halifax, Mandell (1994)
0.3Freshwater Aquatic LifeCCME
0.3Drinking Water- Maximum Acceptable ConcentrationCCME


Mn (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.06 (<0.01-1.2)Average in N.S. lakesHinch & Underwood, 1985 (Mn does not occur naturally as a metal but is present in over 100 common salts and minerals in rocks, soils, and on the floors of lakes and oceans. In natural waters, generally <0.05. Higher levels are either associated with industrial pollution or with reducing conditions such as exist underground and in some lakes and reservoirs [per Health & Welfare Canada, 1980])
0.0715Susies Lake (Dec. 1985)Undisturbed lake in Halifax Metro. Urban et al, 1990
0.05Drinking Water- Maximum Acceptable ConcentrationCCME (Mn is one of the elements least toxic to mammals. At levels exceeding 0.15, Mn stains plumbing fixtures and laundry and causes undesirable tastes in beverages. It is difficult to remove Mn at conc.<0.05 [Health & Welfare Canada, 1980 per Hinch & Underwood, 1985])
<0.01Objective conc. (because of potential deposition and staining even at the max. acceptable level)Health & Welfare Canada, 1980 (per Hinch & Underwood, 1985)


Al (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.145 (0.008-0.55)Average background level for N.S. lakesHinch & Underwood, 1985 (Al- the third most abundant of elements in the earth's crust)
0.230 (calculated from eq/l)Susies Lake (1980-83)Undisturbed lake in Halifax Metro. Kerekes et al, 1986
0.005Freshwater Aquatic LifeCCME (pH<6.5; Ca2+<4.0 mg/l; DOC<2.0 mg/l)
0.1Freshwater Aquatic LifeCCME (pH≥6.5; Ca2+≥4.0 mg/l; DOC≥2.0 mg/l)


As (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
<0.00237 pristine Halifax County lakes (Dec. 1984)John Underwood (pers. comm.). Jan, 1994
≤0.005Objective conc. in drinking waterHinch & Underwood, 1985
0.05Maximum acceptable conc. in drinking waterHinch & Underwood, 1985


Ba (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.017Average conc. in N.S. lakesHinch & Underwood, 1985 (Ca and SO4 are commonly associated with Ba as CO3 and sandstones)
1.0Maximum acceptable conc. in drinking waterHinch & Underwood, 1985
≤0.1Objective conc. in drinking waterHinch & Underwood, 1985


Cd (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.005 - 0.008Average value in natural waters is less than the detection limitHinch & Underwood, 1985. (Cd is a relatively rare element and is nonetheless commonly found in association with Cu, Pb, and Zn. Surface waters having more than a few gCd/l have probably been contaminated by industrial wastes [from metallurgical plants, plating works, plants manufacturing cadmium pigments, textile operations, cadmium-stabilized plastics or nickel cadmium batteries], or by effluents from sewage treatment plants)
0.7Average value in N.S. lake sedimentsHinch & Underwood, 1985
0.005Maximum acceptable conc. in drinking waterHinch & Underwood, 1985
≤0.001Objective conc. in drinking waterHinch & Underwood, 1985


Co (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
<0.01 - 0.08N.S. lake averagesHinch & Underwood, 1985 (majority of Co readings in N.S. lakes are below the detection limit of 0.01)


Cu (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.011
(<0.005 - 0.17)
Average conc. in N.S. lakesHinch & Underwood, 1985 (Cu is ubiquitous [found everywhere] in the environment)
1.0Maximum acceptable conc. in drinking waterHinch & Underwood, 1985 (At higher concentrations Cu stains laundry and plumbing fixtures, and may also impart an undesirable taste to the water and enhance corrosion of Al and Zn)
<1.0Objective conc. in drinking waterHinch & Underwood, 1985


Pb (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.008 (<0.05-0.03)N.S. lake averagesHinch & Underwood, 1985 (Lead is considered a ubiquitous element in the environment)
0.05Maximum acceptable drinking water standardHinch & Underwood, 1985
≤0.001Objective conc. in drinking water 


Zn (mg/l)
Lake Means & GuidelinesLake & SpecificsReferences & Notes
0.014 (<0.01-0.22)Average in N.S. lakesHinch & Underwood, 1985 (Zn is an abundant element in the earth. In addition, various industrial and domestic emissions contribute considerable amounts to the air and water environment [primary iron and steel production, primary copper and nickel production, fuel combustion of coal and heavy oils, solid waste incineration, transportation, and pesticide application are all potential contributors])
5.0Maximum acceptable conc. in drinking waterHinch & Underwood, 1985 (In excess of 5 mg/l, water has an undesirable taste, and may develop a greasy film when boiled)
<5.0Objective conc. in drinking waterHinch & Underwood, 1985


Dissolved Oxygen (DO) (mg/l)
Freshwater Aquatic Life
DO conc. in mg/l (CCME)
Categories of biotaEarly life stagesOther life stages
Warm-water65
Cold-water9.5 (6.5)6.5
(6.5- interstitial water of the gravel)






Freshwater Aquatic Life
DO limits (Davis, NRCC in CCME)
TemperatureWarm-water biotaCold-water biotaPrimarily salmonids
oC% Sat.mg/l% Sat.mg/l% Sat.mg/l
0477548578
5476547577
10475546576
15475546596
20474575656
25484635726


E. coli and fecal coli
GuidelinesSpecificsReference
The geometric mean of at least 5 samples taken during a period of 30 days should not exceed 2000 E. coli per litreRecreational Water QualityCCME


Enterococci
GuidelinesSpecificsReference
The geometric mean of at least 5 samples taken during a period of 30 days should not exceed 350 enterococci per litreRecreational Water QualityCCME


Microorganisms
GuidelinesSpecificsReferences
a) No sample should contain more than 10 total coliform organisms per 100 ml;
b) not more than 10% of the samples taken in a 30 day period should show the presence of coliforms;
c) not more than two consecutive samples from the same site should show the presence of coliforms; and
d) none of the coliform organisms detected should be fecal coliforms
Drinking Water- Maximum Acceptable ConcentrationCCME



References


Lake Data Archives                   Soil & Water Conservation Society of Metro Halifax (SWCSMH) Master Homepage


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