19:15 | 05/25/15
Experts call for urgent construction of wastewater treatment facilities in West Bank
Water dripping from a tap (photo credit: ING IMAGE/ASAP)
Cross-border study finds presence of endocrine disrupting chemicals minimal in Israeli, Palestinian treated wastewater.
Although the presence of chemicals that disrupt the endocrine glands that produce some hormones is minimal in both Israeli and Palestinian treated wastewater, facilities that perform such treatment in the West Bank are problematically scarce, experts agreed at a cross-border conference on Monday.
At both the second and tertiary (advanced) level, wastewater treatment plants within the Green Line, and at the secondary level facilities in the West Bank, samplings of purified water in a new study showed only trace amounts of these EDCs – chemicals that scientists say may interfere with the body’s endocrine systems and developmental processes.
At a seminar in the Palestinian town of Beit Sahur, east of Bethlehem, on Monday, researchers from both sides of the Green Line presented the results of a three-year study on both the presence of and the potential environmental health impacts of these EDCs in Israeli and Palestinian water resources.
Led by Prof. Alon Tal and Dr.
Shai Arnon from the Ben-Gurion University of the Negev, Dr.
Alfred Abed-Rabbo from Bethlehem University and engineer Nader al-Khateeb of the Bethlehem-based Water and Environmental Development Organization, the study was conducted in collaboration with the Israeli Health Ministry.
The work was sponsored by the United States Agency for International Development’s (USAID) Middle East Regional Cooperation (MERC) program, which works to facilitate peaceful cooperation between Arab and Israeli scientists.
While Israel has 74 wastewater treatment plants, serving 8 million people, the West Bank has only two functional plants serving 2.8 million, Tal explained.
“Endocrine-disrupting chemicals exist in Israeli and Palestinian sewage, but they are largely removed down to minimal levels by secondary sewage treatment,” he said.
“There may be long-term negative environmental impacts from recycling sewage effluents, but exposing humans to high levels of endocrine disrupting compounds is not one of them.”
EDCs can reach underground water resources through many vehicles, such as industrial practices, pesticide and wastewater, with potentially adverse health effects and even transgenerational impacts, explained Wa’ad Odeh, a master’s degree candidate under Arnon, from Ben-Gurion University’s Zuckerberg Institute for Water Research.
Odeh examined the occurrence and concentrations of EDCs in West Bank raw sewage, in three streams, in groundwater and in effluents from wastewater treatment plants – those in Jenin, Tulkarm, El-Bireh and west Nablus. Citing Palestinian Water Authority data, Odeh said that the total wastewater produced in the Palestinian areas of the West Bank amounts to approximately 62 million cubic meters per year, of which less than 10 percent is treated and less than 1% is reused.
Odeh examined the presence of 10 EDCs as well as carbamazepine – an anticonvulsant used to treat seizures – as a marker. In addition to carbamazepine, she found six EDCs in raw effluent, with estrone – a kind of estrogen – occurring in the greatest amounts.
While these compounds were present in raw sewage, Odeh said they were not found in groundwater. Meanwhile, secondary wastewater treatment plants demonstrated high removal efficiencies for EDCs, effectively removing the compounds – though not entirely in all cases – from the purified end product, she explained.
While estrogenic activity in West Bank sewage poses a hazard, the removal process makes treated wastewater safe, Odeh concluded. However, at the moment there are only two functioning secondary wastewater treatment plants in the West Bank (two others are not working), and many contaminated waterways.
“These streams are so hazardous,” Odeh said. “After removal they become good, but leaving them as is right now is not a good situation. And the West Bank is covered by these wastewater streams.”
Odeh’s colleague in Arnon’s laboratory, Tal Godinger, performed similar research within the Green Line, taking samples from six Israeli wastewater treatment plants in the winters and summers of 2013 and 2014. Godinger also used carbamazepine as a marker and identified estriol, estrone and triclosan as the most common EDCs in raw sewage.
Like Odeh, Godinger said she found that the wastewater treatment plants almost completely removed the EDCs from the resultant water, though estrone appeared in high levels at one plant in Yad Hanna, in the Hefer Valley, with a less advanced aeration system. Removal of triclosan was also more difficult than that of other EDCs in some cases, Godinger explained, as the compound has a higher hydraulic retention time – the average time that a soluble compound remains an active bioreactor.
All in all, Godinger concluded that the environmental risk posed by EDCs was medium to low.
Another issue is that researchers do not entirely understand the impact of EDCs in a low concentration, Arnon added.
Although there seems to be no risk to humans, Arnon said he cannot express certainty that this is “completely safe.” Another student in his laboratory is evaluating pathways other than water that carry EDCs to the human body, he added.
“This is actually the first time that there was a comprehensive monitoring project aimed at EDCs in the region,” Arnon said, stressing that this was only a preliminary study.
Expanding upon the data obtained by Odeh and Godinger, another Ben-Gurion University student, Nina Gordon- Kirsch, performed a cost effectiveness ratio analysis to determine what type of treatment sites should be the priority in the West Bank, secondary or tertiary. Her mentor Tal, an environmental policy expert at the university, presented her results on her behalf at the Beit Sahur seminar.
Gordon-Kirsch’s study looked at EDC removal percentages at the tertiary wastewater treatment plants in Ra’anana and Hod Hasharon, the secondary wastewater treatment plants in west Nablus and El-Bireh and the nonoperational primary wastewater treatment plant in Tulkarm.
“There’s not a whole lot of difference in terms of the percent removal in the Israeli plants doing the tertiary advanced treatment and the secondary treatment,” Tal said.
Operational costs at the Ra’anana and Hod Hasharon tertiary plants were significantly higher than those at the west Nablus and El-Bireh secondary plants, while the average annual per capita incomes in the West Bank and Israel are about $4,900 and $32,000, respectively, he added.
Taking all of these factors into account, Tal and Gordon- Kirsch have concluded that there are only marginal benefits from moving from secondary to tertiary treatment, and that Palestinian investments would be better spent by investing in basic water infrastructure such as piping.
“Because we saw is that there is such a low level of treatment and practically no reuse, there’s a fundamental challenge – developing basic infrastructure,” agreed Dr. Clive Lipchin, director of the Center for Transboundary Water Management at the Arava Institute for Environmental Studies. “If you don’t have that basic level of infrastructure, then reuse and capturing of wastewater is always going to be a problem and it’s always going to provide these tensions between Israel and Palestine.”
Although acknowledging that there are many benefits from reducing contaminants in addition to EDCs by means of tertiary treatment mechanisms, Tal stressed that the formulation of a wastewater treatment strategy for the Palestinians must be “driven by the fact that 91% of their sewage is still untreated altogether.
“Israel should not try to push Palestinians to upgrade their standards to meet our own, highly demanding, levels,” he said. “Rather, let’s support them in collecting the existing sewage streams and providing solid secondary treatment, which is enough for most irrigation uses, and getting the raw sewage out of the streams and wadis where it can contaminate our common groundwater resources.”
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