Table 3.2 Summary Statistics of Marine Water Quality in the North Western WCZ at Station NM5 for 2000

 

Parameter

 

EPD Monitoring Station (NM5)

WPCO WQOs (in marine waters)

Temperature (oC)

 

23.6

(17.6 – 28.1)

natural daily level ± 2 oC

Salinity (ppt)

 

27.7

(20.4 – 32.2)

natural ambient level ± 10 %

Dissolved Oxygen (DO)

(% saturation)

 

82

(52 – 108)

-

 

Bottom

79

(40 – 110)

-

DO (mg L-1)

 

6.0

(3.7 – 8.6)

³ 4 mg L-1

 

Bottom

5.7

(2.8 – 8.8)

³ 2 mg L-1

pH value

 

7.9

(7.7 – 8.3)

6.5 - 8.5 (± 0.2 from natural range)

Secchi disc (m)

 

1.5

(1.0 – 2.5)

-

Turbidity (NTU)

 

15.3

(4.7 – 39.9)

-

SS (mg L-1)

 

11.1

(2.0 – 26.1)

£ natural ambient level + 30%

Silica (as SiO2)

(mg L-1)

 

1.6

(0.1 – 3.6)

-

BOD5 (mg L-1)

 

0.8

(0.2 – 2.0)

not applicable to marine waters

Nitrite Nitrogen (mg L-1)

 

0.05

(0.01 – 0.13)

-

Nitrate Nitrogen (mg L-1)

 

0.31

(0.10 – 0.82)

-

Ammonia Nitrogen

(mg L-1)

 

0.15

(0.09 – 0.20)

-

Unionised Ammonia

(mg L-1)

 

0.005

(0.002 – 0.014)

£ 0.021 mg L-1

Total Inorganic Nitrogen (mg L-1)

 

0.51

(0.27 – 0.99)

£  0.5 mg L-1

Total Nitrogen

(mg L-1)

 

0.68

(0.45 – 1.20)

-

Ortho-Phosphate (mg L-1)

 

0.03

(0.01 – 0.04)

-

Total Phosphorus

(mg L-1)

 

0.06

(0.04 – 0.08)

-

Chlorophyll-a

(µg L-1)

 

3.8

(0.2 – 25.0)

-

E. coli (cfu per 100 mL)

 

480

(170 – 2300)

< 610 cfu per 100 mL for keeping live seafood

Faecal Coliform

(cfu per 100 mL)

 

1000

(340 – 5300)

-

Notes:

1.              Data are provided by EPD.

2.              Except as specified, data presented are depth-averaged data.

3.              Data presented are arithmetic means except for E. coli and faecal coliforms that are geometric means.

4.              Data enclosed in brackets indicate ranges.

5.            Shaded cells indicate non-compliance with the WQOs.