Geoscience Reference
In-Depth Information
Table 5.3 Major ions, nitrates, BOD (biological oxygen demand) and total suspended sediments
(TSS)
Stormwater
concentration
(mg/l)
TSS
BOD chloride Nitrate Ammonium Sulfate Phosphate
27
26
31
31
27
20
3
Samples No. Land Use
MQL 3
8.6
0.8
MQL
4.81
Minimum
Residential
538
13
50.4
6.4
0.42
15.9
Maximum
163.0
7.6
22.3
3.6
0.2
9.6
0.7
Mean
156.0
2.6
11
1.2
0.1
2.7
Standard
deviation
27
27
31
31
27
23
Samples No.
7
3
12
0.9
MQL
9.9
Minimum
Industrial
784
110
77.4
10.5
4.46
84.8
Maximum
150.4
16.3 50.7
7.5
6.4
16.7
1.4
Mean
207.5
23.4 81.3
8.3
10.2
17.7
Standard
deviation
14
14
18
18
14
12
3
Samples No.
MQL 1
9.2
0.79 MQL
5.29
0.27
Minimum
Major roads
815
25
35.6
5.0
2.87
11.6
0.38
Maximum
182.9
6.8
25.1
3.0
0.4
9.1
0.3
Mean
205.8
6.1
11.8
1.6
0.8
2.4
Standard
deviation
5
5
5
5
5
5
2
Samples No.
MQL 2.5
9.46
3.3
0.15
5.8
0.74
Minimum
Parking
23 9 114 5.4 0.5 19.6 1.06 Maximum
173.75 4.3 33.232 4.388 0.36 9.632 0.9 Mean
1
20
2
250
2
70
1
1.5
2
250
1
1.0 Israeli water
standards
1. Stream
water
2. Drinking
water
Chloride and nitrate concentrations observed in the residential neighborhoods and major roads
were lower than concentrations observed in the industrial area
concentrations were observed in the storm water in the industrial areas, above
drinking water standards for iron and zinc (1.14 and 2.08 mg/L respectively).
Generally, lower concentrations of zinc were found in residential areas than were
observed in industrial areas and roads.
A comparison was made between the average concentrations of heavy metals in
storm water from residential area at Herzlia to other cities in Israel (Rishon Le-Zion
unpublished data) (Fig.
5.7
). The observations received from all the cities is similar,
runoff water in residential areas contains low concentrations of heavy metals and
does not constitute an environmental problem. Heavy metal concentrations in urban
storm water were generally higher in Rishon Le-Zion and Herzliya than in Ashdod.
The cause may be the higher traffic loads in these cities (Fig.
5.7
).
