Appendix D
Summary statistics of
1999 water quality of North Western WCZ (EPD Routine Monitoring Programme)
|
|
Lantau Island North |
Pearl Island |
Pillar Point |
Urmston Road |
Chek Lap Kok (North) (West) |
|
|
Determinand |
NM1 |
NM2 |
NM3 |
NM5 |
NM6 |
NM8 |
|
Number of samples |
12 |
12 |
12 |
12 |
12 |
10 |
|
Temperature (°C) |
23.7 (17.5 – 26.5) |
23.9 (16.9 – 27.9) |
23.7 (17.4 – 27.3) |
23.9 (17.5 – 27.7) |
24.2 (16.3 – 27.7) |
25.4 (19.8 – 28.8) |
|
Salinity (psu) |
29.9 (24.5 – 33.3) |
28.1 (17.3 – 33.3) |
29.2 (22.5 – 33.2) |
27.6 (18.8 – 33.1) |
25/5 (11.1 – 33.7) |
25.5 (12.7 – 33.7) |
|
Dissolved Oxygen
(mg/L)
Depth Average |
5.8 (3.5 – 8.1) |
6.1 (4.3 – 8.7) |
5.9 (3.3 – 8.0) |
6.0 (3.7 – 8.2) |
6.9 (5.0 – 11.8) |
6.8 (4.7 – 11.6) |
|
Bottom |
5.5 (2.4 – 7.8) |
5.8 (3.2 – 8.4) |
5.6 (2.2 – 8.2) |
5.6 (2.3 – 8.3) |
6.9 (5.0 – 11.8) |
6.8 (4.8 – 11.7) |
|
Dissolved Oxygen (%
Saturation) Depth
Average |
81 (49 – 106) |
84 (59 – 114) |
82 (46 – 105) |
83 (51 – 108) |
95 (68 – 167) |
97 (70 – 165) |
|
Bottom |
77 (34 – 101) |
81 (46 – 109) |
79 (32 – 107) |
79 (33 – 108) |
95 (69 – 167) |
96 (68 – 167) |
|
PH |
8.0 (7.8 – 8.3) |
8.0 (7.8 – 8.3) |
8.0 (7.8 – 8.3) |
8.0 (7.8 – 8.3) |
8.1 (7.8 – 8.5) |
8.1 (7.9 – 8.7) |
|
Secchi Disc Depth
(m) |
1.9 (1.0 – 3.0) |
1.7 (1.0 – 3.0) |
1.5 (1.0 – 3.0) |
1.3 (0.5 – 2.5) |
1.3 (0.8 – 2.5) |
1.2 (0.5 – 1.5) |
|
Turbidity (NTU) |
9.1 (<0.1 – 22.6) |
8.7 (3.2 – 13.5) |
9.9 (3.5 – 14.8) |
13.0 (3.8 – 33.9) |
10.8 (3.4 – 15.6) |
12.9 (6.0 – 23.2) |
|
Suspended Solids
(mg/L) |
7.6 (1.6 – 17.0) |
6.9 (2.3 – 13.7) |
7.5 (2.8 – 14.6) |
14.1 (2.9 – 86.9) |
8.8 (2.8 – 21.0) |
10.8 (3.5 – 20.2) |
|
5-day Biochemical
Oxygen Demand (mg/L) |
0.6 (0.2 – 1.0) |
0.5 (0.2 – 0.9) |
0.6 (0.2 – 0.9) |
0.6 (0.1 – 1.3) |
0.8 (0.3 – 1.8) |
1.0 (0.2 – 4.6) |
|
Ammonia Nitrogen
(mg/L) |
0.08 (0.01 – 0.14) |
0.08 (0.01 – 0.14) |
0.08 (0.01 – 0.15) |
0.08 (0.01 – 0.16) |
0.05 (0.01 – 0.21) |
0.02 (0.01 – 0.06) |
|
Unionized Ammonia
(mg/L) |
0.003 (<0.001 – 0.006) |
0.004 (<0.001 – 0.007) |
0.003 (<0.001 – 0.007) |
0.004 (<0.001 – 0.008) |
0.002 (<0.001 – 0.006) |
0.001 (<0.001 – 0.002) |
|
Nitrite Nitrogen
(mg/L) |
0.04 (0.01 – 0.11) |
0.05 (0.01 – 0.12) |
0.05 (0.01 – 0.13) |
0.06 (0.01 – 0.14) |
0.06 (<0.01 – 0.15) |
0.05 (<0.01 – 0.13) |
|
Nitrate Nitrogen
(mg/L) |
0.21 (0.04 – 0.53) |
0.28 (0.04 – 0.84) |
0.23 (0.04 – 0.61) |
0.33 (0.03 – 0.83) |
0.36 (0.01 – 1.05) |
0.37 (0.01 – 1.03) |
|
Total Inorganic
Nitrogen (mg/L) |
0.34 (0.17 – 0.64) |
0.41 (0.13 – 0.97) |
0.35 (0.14 – 0.75) |
0.47 (0.15 – 0.96) |
0.47 (0.05 – 1.24) |
0.44 (0.04 – 1.17) |
|
Total Kjeldah
Nitrogen (mg/L0 |
0.31 (0.20 – 0.54) |
0.29 (0.18 – 0.59) |
0.27 (0.17 – 0.40) |
0.28 (0.14 – 0.46) |
0.28 (0.09 – 0.49) |
0.25 (0.10 – 0.52) |
|
Total Nitrogen
(mg/L) |
0.57 (0.30 – 0.86) |
0.62 (0.28 – 1.15) |
0.54 (0.28 – 0.96) |
0.67 (0.28 – 1.25) |
0.70 (0.18 – 1.53) |
0.67 (0.18 – 1.33) |
|
Ortho-phosphate
(mg/L) |
0.03 (0.02 – 0.04) |
0.03 (0.02 – 0.05) |
0.03 (0.02 – 0.??) |
0.03 ((0.02 – 0.05) |
0.02 (0.01 – 0.07) |
0.02 (0.01 – 0.04) |
|
Total Phosphorus
(mg/L) |
0.05 (0.03 – 0.06) |
0.04 (0.03 – 0.06) |
0.04 (0.03 – 0.06) |
0.05 (0.03 – 0.11) |
0.04 (0.02 – 0.07) |
0.04 (0.02 – 0.06) |
|
Silica (as SiO2)
(mg/L) |
1.4 (0.3 – 3.1) |
1.6 (0.2 – 4.1) |
1.3 (0.2 – 3.5) |
1.8 (0.2 – 4.4) |
1.8 (0.2 – 5.5) |
1.9 (0.3 – 5.2) |
|
Chlorophyll-a (mg/L) |
2.8 (0.5 – 9.4) |
2.7 (0.7 – 10.3) |
2.5 (0.7 – 5.0) |
3.3 (0.8 - 13.6) |
4.9 (0.5 – 26.3) |
6.7 (0.6 – 42.0) |
|
Phaeo-pigment (mg/L) |
0.6 (0.2 – 1.5) |
0.7 (0.2 – 2.5) |
0.7 (0.2 – 2.5) |
0.8 (0.2 – 1.6) |
1.5 (0.2 – 7.0) |
3.2 (0.2 – 24.0) |
|
E.coli (cfu/100mL) |
360 (94 – 1500) |
190 (39 – 1200) |
680 (88 – 6300) |
360 (72 – 1400) |
13 (1 – 200) |
3 (1 – 22) |
|
Faecal Coliforms
(cfu/100mL) |
920 (220 – 4600) |
460 (110 – 2900) |
1500 (160 – 12000) |
740 (160 – 2600) |
33 (4 – 470) |
8 (1 – 1700) |
Note
: 1. Except as specified, data presented
are depth-averaged results.
2.
Depth-averaged
results at each station are calculated as arithematic means of measurements at
all available depths (i.e. S, M, B) except for E.coli and faecal coliforms which are geometric means.
3.
Data presented are
annual arithmetic means except for E.coli
and faecal coliforms which are annual geometric means.
4.
Data enclosed in
brackets indicate the ranges.
Appendix D
Summary statistics of
water quality of North Western WCZ in 2000 (EPD Routine Monitoring Data)
|
|
Lantau Island North |
Pearl Island |
Pillar Point |
Urmston Road |
Chek Lap Kok (North) (West) |
|
|
Determinand |
NM1 |
NM2 |
NM3 |
NM5 |
NM6 |
NM8 |
|
Number of samples |
12 |
12 |
12 |
12 |
12 |
12 |
|
Temperature (°C) |
23.3 (17.0 – 27.9) |
23.4 (16.9 – 27.9) |
23.4 (17.4 – 28.0) |
23.6 (17.6 – 28.1) |
23.6 (17.1 – 28.2) |
23.4 (16.4 – 28.4) |
|
Salinity (psu) |
30.0 (26.2 – 32.8) |
29.5 (25.9 – 32.8) |
29.5 (26.7 – 32.7) |
27.7 (20.4 – 32.2) |
27.6 (16.1 – 32.7) |
29.6 (21.3 – 32.6) |
|
Dissolved Oxygen
(mg/L)
Depth Average |
5.9 (4.1 – 8.1) |
5.8 (4.0 – 8.3) |
5.9 (3.5 – 8.1) |
6.0 (3.7 – 8.6) |
6.2 (4.6 – 9.3) |
6.3 (4.3 – 8.3) |
|
Bottom |
5.8 (3.6 – 8.7) |
5.8 (3.8 – 8.4) |
5.8 (3.0 – 8.6) |
5.7 (2.8 – 8.8) |
6.2 (4.7 – 9.2) |
6.2 (3.9 –8.2) |
|
Dissolved Oxygen (%
Saturation) Depth Average |
82 (59 – 103) |
80 (60 – 104) |
8.1 (50 –103) |
82 (52 – 108) |
86 (65 – 118) |
87 (63 – 106) |
|
Bottom |
81 (52 – 109) |
7 (54 – 106) |
70 (43 – 108) |
79 (40 –110) |
86 (66 – 116) |
86 (58 – 105) |
|
pH |
7.9 (7.7 – 8.2) |
7.9 (7.7 – 8.3) |
7.9 (7.7 – 8.3) |
7.9 (7.7 – 8.3) |
8.0 (7.7 – 8.3) |
8.0 (7.8 – 8.3) |
|
Secchi Disc Depth
(m) |
2.9 (1.5 - 6.0) |
2.2 (1.5 – 4.0) |
2.0 (1.5 – 4.0) |
1.5 (1.0 – 2.5) |
1.6 (1.0 – 2.5) |
1.4 (0.5 – 2.5) |
|
Turbidity (NTU) |
11.0 (1.2 – 24.0) |
10.7 (1.1 – 25.4) |
11.9 (1.8 – 29.8) |
15.3 (4.7 – 39.9) |
12.7 (1.2 – 26.2) |
17.5 (1.4 – 44.1) |
|
Suspended Solids
(mg/L) |
7.8 (1.5 – 20.8) |
7.9 (1.7 – 16.7) |
10.3 (1. – 20.3) |
11.1 (2.0 – 26.1) |
9.4 (4.0 – 18.5) |
15.6 (3.0 – 32.3) |
|
5-day Biochemical
Oxygen Demand (mg/L) |
0.8 (0.2 – 1.6) |
0.6 (0.1 – 1.6) |
0.6 (0.1 – 1.7) |
0.8 (0.2 – 2.0) |
0.6 (0.1 –1.7) |
0.6 (0.1 – 1.8) |
|
Ammonia Nitrogen
(mg/L) |
0.10 (0.07 – 0.14) |
0.10 (0.07 – 0.15) |
0.10 (0.06 – 0.15) |
0.15 (0.09 – 0.20) |
0.10 (0.06 – 0.23) |
0.06 (0.01 – 0.08) |
|
Unionized Ammonia
(mg/L) |
0.004 (0.002 – 0.008) |
0.004 (0.002 – 0.011) |
0.004 (0.002 – 0.010) |
0.005 (0.002 – 0.014) |
0.004 (0.001 – 0.010) |
0.002 (<0.001 –0.006) |
|
Nitrite Nitrogen
(mg/L) |
0.03 (0.01 – 0.07) |
0.03 (0.01 – 0.07) |
0.04 (0.01 – 0.10) |
0.05 (0.01 – 0.13) |
0.04 (0.01 – 0.12) |
0.03 (0.01 – 0.06) |
|
Nitrate Nitrogen
(mg/L) |
0.20 (0.08 – 0.48) |
0.22 (0.07 – 0.50) |
0.22 (0.06 – 0.46) |
0.32 (0.10 – 0.82) |
0.31 (0.07 – 1.01) |
0.22 (0.04 – 0.89) |
|
Total Inorganic
Nitrogen (mg/L) |
0.34 (0.19 – 0.61) |
0.36 (0.20 – 0.67) |
0.35 (0.16 –0.59) |
0.51 (0.27 – 0.99) |
0.45 (0.17 – 1.20) |
0.31 (0.12 – 1.02) |
|
Total Kjeldahl
Nitrogen (mg/L0 |
0.24 (0.13 – 0.36) |
0.26 (0.17 – 0.34) |
0.25 (0.15 – 0.32) |
0.32 (0.23 – 0.47 |
0.25 (0.16 – 0.42) |
0.20 (0.1 4- 0.26) |
|
Total Nitrogen
(mg/L) |
0.48 (0.26 – 0.77) |
0.52 (0.30 – 0.81) |
0.51 (0.29 – 0.81) |
0.68 (0.45 – 1.20) |
0.60 (0.30 – 1.39) |
0.44 (0.21 – 1.21) |
|
Ortho-phosphate
Phosphorus (mg/L) |
0.03 (0.01 – 0.04) |
0.03 (0.01 – 0.04) |
0.03 (0.01 – 0.04) |
0.03 (0.01 – 0.04) |
0.02 (0.01 – 0.04) |
0.02 (0.01
– 0.03) |
|
Total Phosphorus
(mg/L) |
0.05 (0.03 – 0.07) |
0.05 (0.03 – 0.06) |
0.05 (0.03 – 0.07) |
0.06 (0.04 – 0.08) |
0.05 (0.03 – 0.08) |
0.04 (0.03 – 0.08) |
|
Silica (as SiO2)
(mg/L) |
1.2 (0.1 – 2.5) |
1.2 (0.1 – 2.5) |
1.3 (0.1 – 2.4) |
1.6 (0.1 – 3.6) |
1.6 (0.1 – 4.4) |
1.3 (0.3 – 3.7) |
|
Chlorophyll-a (mg/L) |
3.8 (1.0 – 16.3) |
3.8 (0.5 – 20.3) |
3.8 (0.4 –22.3) |
3.8 (0.2 – 25.0) |
3.7 (0.2 – 21.0) |
2.6 (0.2 – 8.9) |
|
E.coli (cfu/100mL) |
290 (120 – 940) |
360 (100 – 1200) |
320 (75 – 1300) |
480 (170 – 2300) |
39 (6 – 340) |
3 (1 – 14) |
|
Faecal Coliforms
(cfu/100mL) |
720 (230 – 2200) |
820 (140 – 3800) |
730 (190 – 3800) |
1000 (340 – 5300) |
85 (14 – 680) |
6 (1 – 65) |
Note
: 1. Except as specified, data presented
are depth-averaged (A) values calculated by taking the means of three depths :
Surface (S), Mid-depth (M), Bottom (B).
2.
Data presented are
annual arithmetic means of depth-averaged results except for E.coli and faecal coliforms which are
annual geometric means.
3.
Data enclosed in
brackets indicate the ranges.