Environment Agency - Home

Nutrients

We analyse samples for nitrate and orthophosphate. We assign a grade for each nutrient as shown in these tables.

Nutrients

Classification for phosphate

Grade limit (mgP/I) average

Description

1

0.02

Very low

2

0.06

Low

3

0.1

Moderate

4

0.2

High

5

1.0

Very high

6

>1.0

Excessively high

Classification for nitrate

Grade limit (mg NO3/I) average

Description

1

5

Very low

2

10

Low

3

20

Moderately low

4

30

Moderate

5

40

High

6

>40

Very high