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 .