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Background lakes and comparisons in Nova Scotia, Guidelines

Updated: January 25, 2020                      Homepage

Select data is available in the OneDrive's public folder:-
Freshwaters & Marine= https://1drv.ms/f/s!Au0xeIA-MCofgT6hH_HmNC5EW7Oe

Primary Index:



Reference lake types used as indicator thresholds of anthropogenic stressors (Mandell, 1994)

The data of the three following protected lakes within Atlantic Canada's National Parks can be used as a baseline comparison with lakes across Nova Scotia, perhaps all across Atlantic Canada. The fecal coliform counts relate to other drinking water lakes obtained from the Nova Scotia Health Authority by Mandell.


Reference lakes

Phosphorus comparisons of 80 representative lakes within HRM

Download the MS Excel file: This file includes our modelled hindcast values, the pre-industrial diatom inference and modelled values of other lead researchers, historical field data as well as HRM's synoptic data, and HRM's thresholds along with the CCME guidelines.

We had modelled approximately one thousand lakes/ponds over 1 ha in size
for phosphorus, mostly within HRM: all the models are available in the aforementioned OneDrive.



Secondary Index:

(Also see 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 & Guidelines Lake & Specifics References & Notes
85 SD 192 175 Halifax Co. lakes Alexander et al, 1986
89 SD 279 781 Nova Scotia lakes Alexander et al, 1986


Maximum Depth (m)
Lake Means & Guidelines Lake & Specifics References & Notes
10.6 SD 8.4 175 Halifax Co. lakes Alexander et al, 1986
8.2 SD 6.8 772 Nova Scotia lakes Alexander et al, 1986


Mean Depth (m)
Lake Means & Guidelines Lake & Specifics References & Notes
3.1 SD 2.4 118 Halifax Co. lakes Alexander et al, 1986
2.8 SD 2.1 660 Nova Scotia lakes Alexander et al, 1986


Total Phosphorus, TP (as Phosphorus g/l)
Lake Means & Guidelines Lake & Specifics References & 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
4 Clear-water Pockwock Lake (1991-92; 4 events; TSI[TP]=24, TSI[Cha]=24]) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
5 Clear-water Bell Lake (1991-92; 30 events; TSI[TP]=27, TSI[Cha]=34) Clear-water, urban lake in Dartmouth, Mandell (1994)
6 Clear-water Bell Lake (1990; 3 events; TSI[TP]=30, TSI[Cha]=26) Clear-water, urban lake in Dartmouth, SWCS (1991)
2 Clear-water Chocolate Lake (1991-92; 4 events; TSI[TP]=14, TSI[Cha]=11]) Clear-water, urban lake in Halifax, Mandell (1994)
3.8 Clear-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, 6.0 Clear-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
9.1 Coloured-water Kejimkujik Lake (near surf. yearly means) Undisturbed, colored-water lake in a National Park, Kerekes (1975)
10.4, 10.4 Coloured-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 10 17 Keji Park lakes Kerekes. 1975




Environment Canada, 2004: Canadian Guidance Framework
< 4 Ultra-oligotrophic Almost nil impairment of multi-purpose use of lake
4-10 Oligo-mesotrophic Little impairment of multi-purpose use of lake
10-35 Meso-eutrophic Variable impairment of multi-purpose use of lake
35-100 Eutrophic Great impairment of multi-purpose use of lake
> 100 Hypereutrophic Extreme 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 < 2.5 Ultra-oligotrophic Almost nil impairment of multi-purpose use of lake
mean = 2.5-8 Oligotrophic Little impairment of multi-purpose use of lake
mean = 8-25 Mesotrophic Variable impairment of multi-purpose use of lake
mean= 25-80 Eutrophic Great impairment of multi-purpose use of lake
mean > 80 Hypertrophic Extreme impairment of multi-purpose use of lake


TP (mg/l) in sediments
Lake Means & Guidelines Lake & Specifics References & Notes
1.2 Natural lakes of Nova Scotia Underwood and Josselyn, 1979


PO4-P (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.001 SD 0.001 234 N.S. lakes Underwood et al, 1986


Mean Chlorophyll-a (g/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.53 Clear-water Pockwock Lake (1991-92; 4 events; TSI[TP]=24, TSI[Cha]=24) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
1.41 Clear-water Bell Lake (1991-92; 30 events; TSI[TP]=27, TSI[Cha]=34) Clear-water, urban lake in Dartmouth, Mandell (1994)
0.6 Clear-water Bell Lake (1990; 3 events; TSI[TP]=30, TSI[Cha]=26) Clear-water, urban lake in Dartmouth, SWCS (1991)
0.14 Clear-water Chocolate Lake (1991-92; 4 events; TSI[TP]=14, TSI[Cha]=11]) Clear-water, urban lake in Halifax, Mandell (1994)
1.4 Clear-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, 1.03 Clear-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)
2.1 Coloured-water Kejimkujik Lake (near surf. yearly means) Undisturbed, colored-water lake in a National Park, Kerekes (1975)
1.16, 0.93 Coloured-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 lakes Kerekes, 1975
1.3 5 Terra Nova Park lakes, NFLD Kerekes, 1975
3 Lakes in the Canadian Shield in NW Ontario Kerekes, 1975




Environment Canada, 2004: Canadian Guidance Framework
< 1 Ultra-oligotrophic Almost nil impairment of multi-purpose use of lake
< 2.5 Oligo-mesotrophic Little impairment of multi-purpose use of lake
2.5-8 Meso-eutrophic Variable impairment of multi-purpose use of lake
8-25 Eutrophic Great impairment of multi-purpose use of lake
> 25 Hypereutrophic Extreme 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 < 0.7 Ultra-oligotrophic Almost nil impairment of multi-purpose use of lake
mean = 0.7-2.1 Oligotrophic Little impairment of multi-purpose use of lake
mean = 2.1-6.25 Mesotrophic Variable impairment of multi-purpose use of lake
mean= 6.25-19.2 Eutrophic Great impairment of multi-purpose use of lake
mean > 19.2 Hypertrophic Extreme impairment of multi-purpose use of lake


Maximum Chlorophyll-a (g/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.73 Clear-water Pockwock Lake (1991-92; 4 events; TSI[TP]=24, TSI[Cha]=24) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
3.33 Clear-water Bell Lake (1991-92; 30 events; TSI[TP]=27; TSI[Cha]=34) Clear-water, urban lake in Dartmouth, Mandell (1994)
0.74 Clear-water Bell Lake (1990; 3 events; TSI[TP]=30, TSI[Cha]=26) Clear-water, urban lake in Dartmouth, SWCS (1991)
0.23 Clear-water Chocolate Lake (1991-92; 4 events; TSI[TP]=14, TSI[Cha]=11]) Clear-water, urban lake in Halifax, Mandell (1994)
3.27, 2.24 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)
2.80, 1.92 Coloured-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
< 2.5 Ultra-oligotrophic Almost nil impairment of multi-purpose use of lake
< 8 Oligo-mesotrophic Little impairment of multi-purpose use of lake
8-25 Meso-eutrophic Variable impairment of multi-purpose use of lake
25-75 Eutrophic Great impairment of multi-purpose use of lake
> 75 Hypereutrophic Extreme impairment of multi-purpose use of lake





Total Nitrogen, TN (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.19 SD 0.09 37 pristine Halifax Co. lakes (Dec. 1984) John Underwood (pers. comm.), Jan. 1994
0.09 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
0.06 Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth. Mandell (1994)
0.2 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)
0.145, 0.152 Beaverskin 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, 0.17 Coloured-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)
≤0.3 Oligotrophic systems Underwood & Josselyn, 1979


Nitrate-N (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.02 SD 0.03 37 pristine Halifax County lakes (Dec. 1984) John Underwood (pers. comm.) Jan, 1994
<0.19 Susies Lake (1980-83) Undisturbed lake in Halifax Metro, Kerekes et al, 1986
10.0 as N Drinking Water- Maximum Acceptable Concentration CCME- Where both nitrate and nitrite are present the total nitrate- plus nitrite-nitrogen should not exceed 10


Nitrite-N (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.06 Freshwater Aquatic Life CCME guidelines
1.0 as N Drinking Water- Maximum Acceptable Concentration CCME- Where both nitrate and nitrite are present the total nitrate- plus nitrite-nitrogen should not exceed 10


Ammonia, NH4-N (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.007 SD 0.019 37 pristine Halifax Co. lakes (Dec. 1984) John Underwood (pers. comm.). Jan, 1994


Clarity (as Secchi disk depth in m)
Lake Means & Guidelines Lake & Specifics References & Notes
2.9 N.S. Average Underwood & Josselyn, 1979
Minimum visibility at 1.2 Recreational Water Quality CCME guidelines
Environment Canada, 2004: Canadian Guidance Framework
mean > 12
min. > 6
Ultra-oligotrophic Almost nil impairment of multi-purpose use of lake
mean > 6
min. > 3
Oligo-mesotrophic Little impairment of multi-purpose use of lake
mean = 6-3
min. = 3-1.5
Meso-eutrophic Variable impairment of multi-purpose use of lake
mean= 3-1.5
min. = 1.5-0.7
Eutrophic Great impairment of multi-purpose use of lake
mean < 1.5
min. < 0.7
Hypereutrophic Extreme impairment of multi-purpose use of lake





Turbidity
Lake Means & Guidelines Lake & Specifics References & Notes
0.92 SD 0.45 NTU 37 pristine Halifax Co. lakes (Dec. 1984) John Underwood (pers. comm.). Jan, 1994
1.05 SD 0.60 NTU 234 N.S. lakes Underwood et al, 1986
1 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
1 Clear-water Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth, Mandell (1994)
0 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)
5.0 NTU maximum increase Recreational Water Quality CCME guidelines- Maximum allowable increase over natural turbidity when turbidity is low (<50 NTU)


TSS (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
3 Average background conc. of N.S. lakes Hinch & 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 10.0 Freshwater Aquatic Life CCME guidelines- when background suspended solids ≤100.0
Maximum increase of 10% above background Freshwater Aquatic Life CCME guidelines- when background suspended solids >100.0


TDS (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
<30 Natural 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 material Hinch & 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. lakes Hinch & Underwood, 1985
500 Maximum Canadian objective drinking water standard Hinch & Underwood, 1985


Colour
Lake Means & Guidelines Lake & Specifics References & Notes
45 SD 48 TCU 37 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])
5 Susies Lake (1980-83) Undisturbed lake in Halifax Metro. Kerekes et al, 1986
5 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
2 Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth. Mandell (1994)
4 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)
44.5 SD 54.6 TCU 234 N.S. lakes Underwood et al, 1986
15 TCU Drinking Water- Maximum Acceptable Concentration CCME guidelines


TOC (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
8 (0.7 - 20) Pristine N.S. lakes Hinch & 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 & Guidelines Lake & Specifics References & Notes
6.5 SD 6.4 37 pristine Halifax County lakes (Dec. 1984) John Underwood (pers. comm. Jan, 1994)
2.7 Susies Lake (Dec, 1985) Undisturbed lake in Halifax Metro. Urban et al, 1990
1.8 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
0.3 Clear-water Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth, Mandell (1994)
0.45 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)
5.73 SD 3.57 234 N.S. lakes Underwood et al, 1986
5.0 Drinking Water OME- Aesthetic Objective


Conductivity (S/cm)
Lake Means & Guidelines Lake & Specifics References & Notes
62.5 SD 32.0 37 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])
45.6 Susies Lake (Dec. 1985) Undisturbed lake in Halifax Metro. Urban et al, 1990
58.0 SD 74.8 159 Halifax County lakes Alexander et al, 1986
33 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
49 Clear-water Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth, Mandell (1994)
500 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)
69.5 SD 493.0 638 N.S. lakes Alexander et al, 1986
46.9 SD 23.8 234 N.S. lakes Underwood et al, 1986
<5 Distilled water  
20 to 40 Keji Park lakes Tordon (Environment Canada)
70 to 90 Halifax City tapwater McCarthy
30,000 + Seawater  


pH
Lake Means & Guidelines Lake & Specifics References & Notes
4.9 SD 0.56 37 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
5.32 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
5.67 Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth. Mandell (1994)
5.21 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)
5.7 SD 0.57 234 N.S. lakes Underwood et al, 1986
6.2 SD 0.6 167 Halifax County lakes Alexander et al, 1986
6.2 SD 0.8 730 N.S. lakes Alexander et al, 1986
5.0 to 9.0 Recreational Water Quality CCME guidelines
6.5 to 9.0 Freshwater Aquatic Life CCME guidelines
6.5 to 8.5 Drinking Water- Maximum Acceptable Concentration CCME guidelines


SO4 (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
5.9 SD 2.2 37 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
6 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
9.6 Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth. Mandell (1984)
39 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)
500 Drinking Water- Maximum Acceptable Concentration CCME guidelines


Alkalinity (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.19 SD 0.38 37 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])
0 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
0.09 Clear-water Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth, Mandell (1994)
0 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)
No decrease >25% Water Quality Objectives OME- should not be decreased by more than 25% of the natural concentration


Hardness as CaCO3 (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
80-100 Acceptable balance between corrosion and incrustration Hinch & 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)
0-60 Soft water Health & Welfare Canada, 1980 (per Hinch & Underwood, 1985)
60-120 Medium hard Water Health & Welfare Canada, 1980 (per Hinch & Underwood, 1985)
120-180 Hard water Health & Welfare Canada, 1980 (per Hinch & Underwood, 1985)
180 and above Very hard water Health & Welfare Canada, 1980 (per Hinch & Underwood, 1985)
7.1 SD 4.1 37 pristine Halifax County lakes (Dec. 1984) John Underwood (pers. comm.). Jan, 1994


Cl (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
10.3 SD 6.7 37 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
6.2 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
9 Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth. Mandell (1994)
148 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)
250 Drinking Water- Maximum Acceptable Concentration CCME


Na (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
6.3 SD 4.1 37 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
3.8 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
4.9 Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth. Mandell (1994)
88 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)


K (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.41 SD 0.15 37 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
0.39 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
0.73 Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth. Mandell (1994)
4.5 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)


Ca (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
1.6 SD 0.95 37 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
1.4 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
2.6 Bell Lake (1991-92; 30 events) Clear-water, urban lake in Dartmouth.Mandell (1994)
13 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)


Mg (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.78 SD 0.41 37 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
1 Clear-water Pockwock Lake (1991-92; 4 events) Clear-water, water supply lake in Hammonds Plains, Mandell (1994)
1 Bell Lake (1991-92; 30 events) Relatively undisturbed, clear-water, urban lake in Dartmouth. Mandell (1994)
2 Clear-water Chocolate Lake (1991-92; 4 events) Clear-water, urban lake in Halifax, Mandell (1994)


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


Mn (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.06 (<0.01-1.2) Average in N.S. lakes Hinch & 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])
0.0715 Susies Lake (Dec. 1985) Undisturbed lake in Halifax Metro. Urban et al, 1990
0.05 Drinking Water- Maximum Acceptable Concentration CCME (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])
<0.01 Objective 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 & Guidelines Lake & Specifics References & Notes
0.145 (0.008-0.55) Average background level for N.S. lakes Hinch & 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
0.005 Freshwater Aquatic Life CCME (pH<6.5; Ca2+<4.0 mg/l; DOC<2.0 mg/l)
0.1 Freshwater Aquatic Life CCME (pH≥6.5; Ca2+≥4.0 mg/l; DOC≥2.0 mg/l)


As (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
<0.002 37 pristine Halifax County lakes (Dec. 1984) John Underwood (pers. comm.). Jan, 1994
≤0.005 Objective conc. in drinking water Hinch & Underwood, 1985
0.05 Maximum acceptable conc. in drinking water Hinch & Underwood, 1985


Ba (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.017 Average conc. in N.S. lakes Hinch & Underwood, 1985 (Ca and SO4 are commonly associated with Ba as CO3 and sandstones)
1.0 Maximum acceptable conc. in drinking water Hinch & Underwood, 1985
≤0.1 Objective conc. in drinking water Hinch & Underwood, 1985


Cd (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.005 - 0.008 Average value in natural waters is less than the detection limit Hinch & 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)
0.7 Average value in N.S. lake sediments Hinch & Underwood, 1985
0.005 Maximum acceptable conc. in drinking water Hinch & Underwood, 1985
≤0.001 Objective conc. in drinking water Hinch & Underwood, 1985


Co (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
<0.01 - 0.08 N.S. lake averages Hinch & Underwood, 1985 (majority of Co readings in N.S. lakes are below the detection limit of 0.01)


Cu (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.011
(<0.005 - 0.17)
Average conc. in N.S. lakes Hinch & Underwood, 1985 (Cu is ubiquitous [found everywhere] in the environment)
1.0 Maximum acceptable conc. in drinking water Hinch & 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)
<1.0 Objective conc. in drinking water Hinch & Underwood, 1985


Pb (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.008 (<0.05-0.03) N.S. lake averages Hinch & Underwood, 1985 (Lead is considered a ubiquitous element in the environment)
0.05 Maximum acceptable drinking water standard Hinch & Underwood, 1985
≤0.001 Objective conc. in drinking water  


Zn (mg/l)
Lake Means & Guidelines Lake & Specifics References & Notes
0.014 (<0.01-0.22) Average in N.S. lakes Hinch & 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])
5.0 Maximum acceptable conc. in drinking water Hinch & Underwood, 1985 (In excess of 5 mg/l, water has an undesirable taste, and may develop a greasy film when boiled)
<5.0 Objective conc. in drinking water Hinch & Underwood, 1985


Dissolved Oxygen (DO) (mg/l)
Freshwater Aquatic Life
DO conc. in mg/l (CCME)
Categories of biota Early life stages Other life stages
Warm-water 6 5
Cold-water 9.5 (6.5) 6.5
(6.5- interstitial water of the gravel)






Freshwater Aquatic Life
DO limits (Davis, NRCC in CCME)
Temperature Warm-water biota Cold-water biota Primarily salmonids
oC % Sat. mg/l % Sat. mg/l % Sat. mg/l
0 47 7 54 8 57 8
5 47 6 54 7 57 7
10 47 5 54 6 57 6
15 47 5 54 6 59 6
20 47 4 57 5 65 6
25 48 4 63 5 72 6


E. coli and fecal coli
Guidelines Specifics Reference
The geometric mean of at least 5 samples taken during a period of 30 days should not exceed 2000 E. coli per litre Recreational Water Quality CCME


Enterococci
Guidelines Specifics Reference
The geometric mean of at least 5 samples taken during a period of 30 days should not exceed 350 enterococci per litre Recreational Water Quality CCME


Microorganisms
Guidelines Specifics References
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 Concentration CCME



References


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


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