Perceptions on the use of recycled water for produce irrigation and household tasks: A comparison between Israeli and Palestinian consumers.

Water scarcity has resulted in extensive wastewater recycling for agricultural irrigation in both Israel and the Palestinian Territories. However, minimal data have been collected regarding perceptions about wastewater recycling between the populations in these two areas. While geographically close and economically linked, these two populations differ in terms of governance, income, and access to technology for wastewater recycling. To address the data gap pertaining to perceptions of wastewater recycling, a survey was administered among a convenience sample of subjects (n = 236) recruited from Eilat, Israel and Bethlehem, West Bank, from May to November 2018. The survey included questions addressing knowledge of water sources, water scarcity, and recycled water; willingness to use recycled water for produce irrigation and household tasks; and demographics. Israeli willingness to use recycled water for various purposes ranged from 8.3% to 55.1%, and more than half of Israeli respondents were willing to serve both raw and cooked produce irrigated with recycled water. Willingness to use recycled water ranged from 28.9% to 41.7% among the Palestinian respondents, and Palestinian respondents were more willing to engage in high-contact uses (i.e. drinking and cooking) than Israeli respondents. Among the Israeli respondents, experience or familiarity with wastewater recycling and water contamination were frequently significantly associated with willingness to use recycled water. In contrast, among Palestinian respondents, personal water contamination experience, home water safety testing, and trust in authorities to monitor recycled wastewater reuse were frequently significantly associated with willingness to use recycled water. Given the likely increasing water stress in both Israel and the Palestinian Territories, as well as the continued evolution of wastewater treatment technologies and the substantial amount of agricultural trade ongoing between Israel and the Palestinian Territories, it is important to identify effective and appropriate outreach and communication strategies to enable successful and acceptable water recycling.

Antibiotic-resistant Escherichia coli and Klebsiella spp. in greywater reuse systems and pond water used for agricultural irrigation in the West Bank, Palestinian Territories.

Treating and reusing greywater for agricultural irrigation is becoming increasingly prevalent in water-scarce regions such as the Middle East. However, the potential for antibiotic-resistant bacteria to be introduced into food systems or the environment via greywater reuse is a potential area of concern. It is known that off-grid treated greywater often has elevated levels of bacteria, however, little is known regarding the prevalence of antibiotic-resistant bacteria in this water source. To address this knowledge gap, samples (n = 61) of off-grid, household greywater (influent), treated greywater effluent, and irrigation pond water were collected between October 2017 and June 2018 from four farms in the West Bank, Palestinian Territories. Samples were tested for pH, turbidity, dissolved oxygen, electrical conductivity, and oxidation reduction potential. Standard membrane filtration was used to enumerate presumptive Escherichia coli, and isolates (n = 88) were purified, confirmed using 16S rRNA sequencing, and subjected to antimicrobial susceptibility testing using microbroth dilution. The majority of influent (76.5%) and effluent (70.6%) samples had detectable presumptive E. coli. Interestingly, the majority of the isolates were confirmed as Klebsiella sp. (n = 37), followed by E. coli (n = 32), and the remainder were classified as other Enterobacteriaceae (n = 19). A higher percentage of effluent isolates were fully susceptible to all tested antibiotics when compared to influent isolates (28.6% vs 18.6%). Resistance was most commonly observed against ampicillin (69.3% of all isolates), trimethoprim-sulfamethoxazole (11.4%), tetracycline (9.1%), and cefazolin (7.9%), and 7.9% of isolates were observed to be multidrug-resistant. While most water quality parameters were within Israeli and Palestinian wastewater reuse requirements, E. coli levels in effluent violated available standards. These findings suggest that, despite observed decreases in bacteria and an overall decrease in isolates expressing antibiotic resistance from influent to effluent, off-grid greywater treatment systems are still a potential source of both susceptible and antibiotic-resistant bacteria in the agricultural environment.

Antibiotic and herbicide concentrations in household greywater reuse systems and pond water used for food crop irrigation: West Bank, Palestinian Territories.

Greywater is increasingly treated and reused for agricultural irrigation in off-grid communities in the Middle East and other water scarce regions of the world. However, there is a dearth of data regarding levels of antibiotics and herbicides in off-grid greywater treatment systems. To address this knowledge gap, we evaluated levels of these contaminants in two types of greywater treatment systems on four farms in the West Bank, Palestinian Territories. Samples of household greywater (influent, n = 23), treated greywater effluent intended for agricultural irrigation (n = 23) and pumped groundwater held in irrigation water ponds (n = 12) were collected from October 2017 to June 2018. Samples were analyzed using high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) for the following antibiotics and herbicides: alachlor, ampicillin, atrazine, azithromycin, ciprofloxacin, erythromycin, linezolid, oxacillin, oxolinic acid, penicillin G, pipemidic acid, sulfamethoxazole, triclocarban, tetracycline, triflualin, and vancomycin. All tested antibiotics and herbicides were detected in greywater influent samples at concentrations ranging from 1.3 to 1592.9 ng/L and 3.1-22.4 ng/L, respectively. When comparing influent to effluent concentrations, removal was observed for azithromycin, alachlor, linezolid, oxacillin, penicillin G, pipemidic acid, sulfamethoxazole, triclocarban, and vancomycin. Removal was not observed for atrazine, ciprofloxacin, erythromycin, oxolinic acid, tetracycline, and trifluralin. Pond water also contained the majority of tested contaminants, but at generally lower concentrations. To our knowledge, this is the first description of an extensive array of antibiotics and herbicides detected in household greywater from off-grid treatment systems.