Geoscience Reference
In-Depth Information
Samples for organic compounds were collected manually from all drains in
preheated (400
C) borosilicate bottles, stored on ice and treated in the laboratory
within 5 days of sampling, to minimize volatilization. Samples collected for
microbiological indicators (general count, coliform bacteria and fecal coliform
bacteria) in 300 mm sterile tube were transferred to analysis within 6 h and treated
in the laboratory on the day of sampling to avoid bacterial growth.
5.3.4 Analyses of Water Samples
The analyses were carried out at authorized laboratories of the Israel Water Commis-
sion, in accordance with the standard methods for chemical and biological analysis.
Major ions were examined using a sealed absorption apparatus, and trace elements
using the ICP-AES (Intunnelively Coupled Plasma-Atomic Emission Spectrometer)
after calibration according to specific standards. The testing of semi-volatile organic
compounds was done according to the EPA method 8270, using the Solid-Phase
Extraction process and GC/MS analysis. The samples were passed through a 0.5
m
glass filter before extraction. During the analysis, 1
l of the sample was injected into
the MS/GC Varian Saturn 2000, connected to a computer and printer; the quanti-
fying of substances characterized as specific pollutants was done using (Authentic
standards). Additional substances discovered in the samples for which we have no
authentic standard were quantified by estimation (a crude estimate) on the basis of the
response of the substance in the GC/MC device in comparison with that of the
internal standards. The microbial analysis to establish the overall numbers, fecal
e-coli and coli forms was carried out according to standard incubation methods on
Petri dishes and counting of microbe colonies (cfc/100 ml)in various dilutions.
m
5.4 Results
5.4.1 Land Use Analysis in Herzliya and Ra'anana
According to the results of the land-use analysis, the impervious area reached
30-40% in the residential areas and 60-75% in the industrial areas. The road
fractions in residential areas reached 13-18%, in the industrial areas only 8% are
roads (Table
5.1
). The area was made up of several sub basins:
The Herzliya industrial basin - consists primarily of light industry, hi-tech,
office buildings as well as garages and commercial areas. The site is made up of
many impervious areas connected directly to the central drainage system. Flows are
characterized by a rapid runoff of rainwater and the creation of short, separate high-
water waves which respond rapidly to each wave of rain.
The closed tunnel residential basin - The basin characterizes residential areas
with a percentage of built-up areas of approx. 40% (Table
5.1
).
This basin is a part of the larger basin called the open tunnel.
