Prairie Provinces Water Board

The most significant interjurisdictional water management arrangement in Canada is the Master Agreement on Apportionment.

1986 Pearse Inquiry on Federal Water Policy

Contact Us

Prairie Provinces Water Board
2365 Albert Street, Room 300
Regina, Saskatchewan S4P 4K1

Telephone: (306) 780-6042
Fax: (306) 780-6810
Email: Lynne.Quinnett-Abbott@ec.gc.ca

www.ppwb.ca

Ammonia

Total Ammonia Nitrogen (mg/L) **

The toxicity of ammonia relates primarily to the un-ionized form (NH3). The concentration of un-ionized ammonia present in water increases with pH and temperature. The values below represent total ammonia-nitrogen concentrations (at various temperatures and pH levels) above which accompanying NH3 concentrations may be harmful to aquatic life.

Total Ammonia (NH3 + NH4+)

(maximum levels expressed as N at various pH/temperature conditions)

Toxicity of Ammonia under varying Temperature and pH Conditions
Water Temperature (°C) / pH
(pH units)

10°

15°

20°

25°

30°

6.50

2.06

1.97

1.81

1.81

1.22

0.85

0.60

6.75

2.06

1.97

1.81

1.81

1.22

0.85

0.61

7.00

2.06

1.97

1.81

1.81

1.22

0.85

0.61

7.25

2.06

1.97

1.81

1.81

1.23

0.86

0.61

7.50

2.06

1.97

1.81

1.81

1.23

0.87

0.62

7.75

1.89

1.81

1.73

1.64

1.15

0.81

0.58

8.00

1.26

1.18

1.13

1.09

0.76

0.54

0.39

8.25

0.72

0.67

0.64

0.62

0.44

0.32

0.23

8.50

0.40

0.39

0.37

0.37

0.26

0.19

0.15

8.75

0.23

0.22

0.21

0.22

0.16

0.12

0.09

9.00

0.13

0.13

0.13

0.13

0.11

0.08

0.06

** excerpt from the "Surface Water Quality Objectives", Water Quality Branch Saskatchewan Environment and Public Safety, November, 1988 (WQ 110)

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