Table 1 Summary of TPH-HMs and environmental parameters in relation to existing ambient water quality criteria.

From: Pollution of the Niger Delta with total petroleum hydrocarbons, heavy metals and nutrients in relation to seasonal dynamics

Chemical ambient water quality criteria for surface waters

Parameters

TPHs (mg/L)

Zn (mg/L)

Al (mg/L)

Cd (mg/L)

Cr (mg/L)

Cu (mg/L)

Fe (mg/L)

Pb (mg/L)

Hg (mg/L)

Ni (mg/L)

pH

PO43− (mg/L)

NO3− (mg/L)

NH4+ (mg/L)

SO42− (mg/L)

Effluent discharge. Irrigation and reuse standards*

na

0.2

0.2

0.01

0.5

0.01

0.5

0.1

0.0005

0.1

6.5–8.5

3.5

40

2

500

Fisheries and recreation quality criteria standards*

na

0.01

0.2

0.005

0.5

0.001

0.05

0.01

0.001

0.001

6.5–8.5

3.5

9.1

0.05

100

USEPA freshwater CCC**

na

0.12

 

0.00072

0.011

na

1

0.0025

0.00077

0.052

6.5–9

na

na

na

na

USEPA saltwater CCC**

na

0.081

 

0.0079

0.05

0.0031

na

0.0081

0.00094

0.082

6.5–8.5

na

na

na

na

Overall mean Estuary stations

311.08

0.020

0.007

0.017

0.011

0.094

0.102

0.008

0.002

0.113

7.63

1.86

3.587

5.55

3.12

SD

147.22

0.023

0.009

0.022

0.014

0.138

0.147

0.020

0.003

0.163

0.47

1.70

4.531

7.33

3.31

Maximum

889.1

0.1

0.033

0.083

0.05

0.564

0.692

0.101

0.013

0.596

8.56

6.09

23.8

30.8

13.75

Overall mean River stations

105.789

0.030

0.021

0.032

0.018

0.212

0.210

0.003

0.009

0.190

8.78

1.83

2.954

4.49

4.26

SD

63.28

0.038

0.052

0.037

0.018

0.247

0.239

0.005

0.012

0.236

0.659

1.90

2.854

5.03

3.54

Maximum

330.26

0.184

0.31

0.141

0.063

0.873

0.965

0.02

0.045

0.896

10.22

6.11

14.16

29.4

12.29

Overall mean Lagoon stations

282.83

0.029

0.028

0.039

0.024

0.247

0.206

0.012

0.009

0.226

8.17

1.99

4.469

8.09

4.79

SD

128.82

0.041

0.062

0.043

0.024

0.267

0.241

0.039

0.017

0.307

0.91

2.33

5.449

10.62

5.56

Maximum

505.45

0.21

0.342

0.167

0.098

0.992

0.74

0.23

0.085

1.276

11.06

8.8

23.8

39.16

25.63

  1. No regulatory values available for the parameters Mn, B, Ba, Co and Mo.
  2. *https://standards.lawnigeria.com/2020/08/18/national-environmental-surface-and-groundwater-quality-control-regulations-2010/ (accessed Nov. 2022)40.
  3. **https://www.epa.gov/wqc/national-recommended-water-quality-criteria-aquatic-life-criteria-table#table (accessed Dec. 2022)41.
  4. Values presented as annual mean from different sites in the estuary, river and lagoon. Values highlighted in bold are exceeding at least one of the regulatory thresholds (SD standard deviation, CCC criterion continuous concentration, na no data available).
Back to article page