Table SM 2. Measurement performance criteria for water quality laboratory analysis done by

the North Dakota Department of Health Laboratory Services.

Analyte / Matrix / Project Action Limit / Project Quantification Limit (QL) / Analytical Method / Achievable Laboratory Limit
MDLs1 / Method / MDLs1 / RLs3
Total Organic Carbon / Water / NA / 0.078 mg/L / EPA 415.35 / 0.078 mg/L / 0.300 mg/L
Total N / Water / NA / 0.015 mg/L / NL2 / 4500-N C4 / 0.015 mg/L / 0.015 mg/L
TKN / Water / NA / NL2 / NL2 / NL2 / NL2 / NL2
Nitrate-nitrite / Water / NA / 0.030 mg/L / NL2 / EPA 353.245 / 0.007 mg/L / 0.030 mg/L
Ammonia / Water / NA / 0.030 mg/L / NL2 / EPA 350.145 / 0.024 mg/L / 0.030 mg/L
Total P / Water / NA / 0.004 mg/L / NL2 / EPA 365.145 / 0.004 mg/L / 0.004 mg/L
Calcium / Water / NA / 0.009 mg/L / 30 µg/L / EPA 200.75 / 0.009 mg/L / 2.00 mg/L
Magnesium / Water / NA / 0.050 mg/L / 30 ug/L / EPA 200.75 / 0.050 mg/L / 1.00 mg/L
Sodium / Water / NA / 0.030 mg/L / 29 ug/L / EPA 200.75 / 0.030 mg/L / 3.00 mg/L
Potassium / Water / NA / 0.140 mg/L / 700 ug/L / EPA 200.75 / 0.140 mg/L / 1.00 mg/L
Iron / Water / NA / 0.009 mg/L / 6.2 ug/L2 / EPA 200.75 / 0.009 mg/L / 0.050 mg/L
Manganese / Water / NA / 0.002 mg/L / 1.4 ug/L2 / EPA 200.75 / 0.002 mg/L / 0.010 mg/L
Conductivity / Water / NA / 0.240 umhos/cm / NL2 / SM 2510 B3 / 0.240 umhos/cm / 4.00 umhos/cm
Chloride / Water / NA / 0.030 mg/L / NL2 / EPA 300.05 / 0.030 mg/L / 0.300 mg/L
Sulfates / Water / NA / 0.070 mg/L / 0.020 mg/L / EPA 300.05 / 0.070 mg/L / 0.300 mg/L
Bicarbonate / Water / NA / NL2 / NL2 / SM 2320 B3 / NL2 / NL2
Carbonate / Water / NA / NL2 / NL2 / SM 2320 B3 / NL2 / NL2
TDS / Water / NA / NL2 / NL2 / SM 1030 F3 / NL2 / NL2
Hardness / Water / NA / NL2 / NL2 / SM 2340 B3 / NL2 / NL2
Alkalinity / Water / NA / 0.570 mg/L / NL2 / SM 2320 B3 / 0.570 mg/L / 3.30 mg/L
Hydroxide / Water / NA / NL2 / NL2 / SM 2340 B3 / NL2 / NL2
TSS / Water / NA / NL2 / NL2 / SM 2540 D3 / NL2 / 5 mg/L
Chloro-a / Water / NA / 1.5 ug/L / NL2 / 10200-H3 / NL2 / 1.5 ug/L
Chloro-b / Water / NA / 1.5 ug/L / NL2 / 10200-H3 / NL2 / 1.5 ug/L

1 Method Detection Limit 6Standards of Quality for Waters of the State of ND (NDDoH, 2014)

2 Not listed in the method 7Method 8000, Dichromate Digestion Method, all ranges

3Reporting Limit 8Lower Detection Limit

3 From Standard Methods, 19th Edition 9Upper Detection Limit

4 From Standard Methods, 20th Edition 10Based on dilution of 10 mL

5 US EPA Clean Water Act Method Approved 11Based on dilution of 0.1 mL