Lakhasly

Abstract The presence of organic compounds in drinking water is well recognized in many developing countries; however, the occurrence of organic contaminants in the groundwater of Saudi Arabia, which is the main source of drinking water in the country, is not well documented.The most relevant compounds in the 71 water samples with respect to highest median and maximum concentrations were 1H-benzotriazole, tris(1-chloro-2- propyl)phosphate (TCPP), methylbenzotriazoles, carbamazepine and its metabolite, DEET, sulfamethoxazole, tris(isobutyl)phosphate (TiBP), tris(2- chloroethyl)phosphate (TCEP), perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and diclofenac.Trihalomethanes (THMs) were the most frequently detected VOC groups; however, a few compounds, such as methyl tert-butyl ether (MTBE), ethylene dibromide (EDB), and dibromochloropropane (DBCP), had regional or local occurrence patterns.The microorganics such as caffeine, N,N-diethyl-m-toluamide (DEET), bisphenol A, anti-microbial agents, pharmaceuticals, and contaminants including chlorinated solvents and THMs, petroleum hydrocarbons, pesticides, and other industrial compounds were detected in the groundwater.Lapworth et al. (2015) presented the results from a reconnaissance survey of micro-organics (MOs) in Chalk groundwater, which included pharmaceuticals, personal care products, and pesticides and their transformation products across the major Chalk aquifers of England and France.These compounds were found in low concentrations, though some of the compounds like imidacloprid, methiocarb, diclofenac, macrolide antibiotics, ciprofloxacin, EHMC, and BHTwere detected in concentrations in excess of 100 ng/L.Manamsa et al. (2016) reported that different types of micro-organic (MO) compounds used for manufacturing, food production, and healthcare were frequently detected in the aquatic environment.Kerndorff et al. (1992) reported that approximately 1200 organic contaminants have been identified in waste disposal site groundwater in Germany and the USA.Among the various chemical substances present in water, organic compounds were detected to varying degrees in some regions of the world to determine their impact on human health (Friesel 1987; Kerndorff et al. 1992).Twenty domestic drinking water wells were tested by Schaider et al. (2016) in a sand and gravel aquifer in Massachusetts, USA, for 117 organic wastewater compounds.A national comprehensive study was carried out to assess the occurrence of organic compounds in groundwater wells used for drinking water purpose, in different regions of Saudi Arabia.Increasing levels of pollution and salinity of groundwater resources is increasingly affecting the ability to use the scarce water resources available (UN-ESCWA and BGR 2013).In general, the concentrations of these compounds in the samples were below the environmental quality standard (EQS) threshold values except the concentration of PFOS, which exceeded the annual average water EQS limit of 0.65 ng/L along the whole river.Most of the wells containing organic compounds were located in residential, industrial, and agriculture areas.A recent boom in the industrial sector has led to the production of different types of inorganic and organic chemicals resulting in drainage disposal of chemical wastes.The presence of chemicals and other organic pollutants in wastewaters can pollute the groundwater through deep percolation (Solomons and Fryhle 2004).They detected 27 organic wastewater compounds which included 12 pharmaceutical and polyfluoroalkyl compounds, and four organophosphate flame retardants.It can be said that the problem of groundwater contamination with organic compounds in Saudi Arabia is not acute and is manageable at present.The widespread occurrence of VOCs indicates the vulnerability of many of the US aquifers to low-level VOC contamination.Keywords Groundwater .Organic compounds .Groundwater contamination .

Abstract The presence of organic compounds in drinking
water is well recognized in many developing countries;
however, the occurrence of organic contaminants
in the groundwater of Saudi Arabia, which is the main
source of drinking water in the country, is not well
documented. A national comprehensive study was carried
out to assess the occurrence of organic compounds
in groundwater wells used for drinking water purpose,
in different regions of Saudi Arabia. A total of 993 well
water samples were collected from all 13 administrative
regions of the kingdom. Samples were analyzed for a
total of 131 organic compounds using the standard
methods. The results indicated that total organic carbon
values were in the range of 0.01 to 84.13 mg/L with an
average weighted value of 12.61 mg/L. Organic compounds
were detected in only 9 regions, with 19.84% of
the samples containing organic compounds. Only 96
wells (9.67%) showed contents of organic compounds
above the safe limits. Pesticides were not detected in any
of the well water samples. Overall, organic compounds
were found in only 197 out of 993 wells (19.84%) in the
whole country. Most of the wells containing organic
compounds were located in residential, industrial, and
agriculture areas. Riyadh region and Eastern Province
were found to have the most affected wells as compared
to other regions. Several regions did not show any
organic compounds in the well waters.
It can be said that the problem of groundwater contamination
with organic compounds in Saudi Arabia is
not acute and is manageable at present. It is, however,
recommended that a regular monitoring of drinking
water wells of all regions should be carried out by the
competent authorities for organic compounds to know
any contamination if and when it happens. Preventing
such contaminants from reaching drinking water
sources and protecting drinking water well heads from
such contaminants remains a priority.
Keywords Groundwater . Organic compounds .
Groundwater contamination . SaudiArabia
Introduction
Water is the most important substance for maintaining
life on earth. It needs proper preservation and
management to safeguard its quality and quantity
for future use. A recent boom in the industrial
sector has led to the production of different types
of inorganic and organic chemicals resulting in
drainage disposal of chemical wastes. The presence
of chemicals and other organic pollutants in wastewaters
can pollute the groundwater through deep
percolation (Solomons and Fryhle 2004). Increasing
levels of pollution and salinity of groundwater resources
is increasingly affecting the ability to use
the scarce water resources available (UN-ESCWA
and BGR 2013).
The quantity, quality, and availability of groundwater
are and will be important environmental issues
concerning the world. Protection, development, and
management of this natural resource are very critical
for preserving this priceless asset. Continued research
by scientists is very important and necessary to preserve
groundwater quality and quantity for future generations
(USGS 2006). Human activities and industrial
development have an impact on groundwater
resources. Every day, a wide range of inorganic and
organic chemicals are manufactured, used, and
disposed of into the environment. Many of these
chemicals, due to their toxicity and harmful effects,
can pollute and deteriorate groundwater if not well
managed. Friesel (1987) estimated that there were some
100,000 chemical compounds of potential concern for
the environment, most of which are organic chemicals.
Kerndorff et al. (1992) reported that approximately
1200 organic contaminants have been identified in
waste disposal site groundwater in Germany and the
USA. In the USA, many of the nation’s aquifers were
found to be vulnerable to volatile organic compounds
(VOCs) (USGS 2006). Almost 20% of the water samples
contained one or more of the 55 VOCs that were
surveyed, at an assessment level of 0.2 μg/L. Trihalomethanes
(THMs) were the most frequently detected
VOC groups; however, a few compounds, such as methyl
tert-butyl ether (MTBE), ethylene dibromide (EDB),
and dibromochloropropane (DBCP), had regional or
local occurrence patterns. The widespread occurrence
of VOCs indicates the vulnerability of many of the US
aquifers to low-level VOC contamination. Other compounds
with widespread sources and similar behavior
and fate properties also may be presented in the aquifers.
Among the various chemical substances present in
water, organic compounds were detected to varying
degrees in some regions of the world to determine their
impact on human health (Friesel 1987; Kerndorff et al.
1992). Lapworth et al. (2015) presented the results from
a reconnaissance survey of micro-organics (MOs) in
Chalk groundwater, which included pharmaceuticals,
personal care products, and pesticides and their
transformation products across the major Chalk
aquifers of England and France. The data from a total
of 345 sites provided the basic assessment of MO
occurrence in groundwater. Manamsa et al. (2016) reported
that different types of micro-organic (MO) compounds
used for manufacturing, food production, and
healthcare were frequently detected in the aquatic
environment. The study provided firsthand information
for the assessment of micro-organic compounds in
groundwater in England and Wales. The microorganics
such as caffeine, N,N-diethyl-m-toluamide
(DEET), bisphenol A, anti-microbial agents, pharmaceuticals,
and contaminants including chlorinated solvents
and THMs, petroleum hydrocarbons, pesticides,
and other industrial compounds were detected in the
groundwater. Loos et al. (2017) investigated the
emerging organic contaminants in water of samples
from the Danube River and its major tributaries. The
most relevant compounds in the 71 water samples
with respect to highest median and maximum concentrations
were 1H-benzotriazole, tris(1-chloro-2-
propyl)phosphate (TCPP), methylbenzotriazoles,
carbamazepine and its metabolite, DEET, sulfamethoxazole,
tris(isobutyl)phosphate (TiBP), tris(2-
chloroethyl)phosphate (TCEP), perfluorooctanoic acid
(PFOA), perfluorooctanesulfonic acid (PFOS), and
diclofenac. In general, the concentrations of these compounds
in the samples were below the environmental
quality standard (EQS) threshold values except the concentration
of PFOS, which exceeded the annual average
water EQS limit of 0.65 ng/L along the whole river.
Twenty domestic drinking water wells were tested by
Schaider et al. (2016) in a sand and gravel aquifer in
Massachusetts, USA, for 117 organic wastewater
compounds. They detected 27 organic wastewater
compounds which included 12 pharmaceutical and
polyfluoroalkyl compounds, and four organophosphate
flame retardants. The concentrations of the couple of
phosphate flame retardants and pharmaceutical
compounds exceeded their concentrations found in the
US drinking water supplies. In France, Colin et al.
(2014) studied the occurrence of 11 alkylphenols and
bisphenols in raw and treated water samples from public
water systems. They reported that the highest individual
concentration was 1430 ng/L for bisphenol A (BPA) in
raw water samples.
The occurrence of emerging organic contaminants
in Spanish groundwaters was reviewed by Jurado et al.
(2019). It was expected that these compounds might
reach the groundwater sources due to their close interaction
with the groundwater. These compounds were
found in low concentrations, though some of the compounds
like imidacloprid, methiocarb, diclofenac,
macrolide antibiotics, ciprofloxacin, EHMC, and
BHTwere detected in concentrations in excess of 100
ng/L.