Driving south along the Dead Sea on Route 90, from Jericho to Ein Gedi, one sees awe-inspiring, thundering waterfalls flowing from the desert plateau to the right, out of a canyon a road sign identifies as Nahal Kidron. The stream then runs strongly toward the salt sea. But a few hundred meters from the road, the flow's stench becomes overwhelming. Its water is brown, and its banks littered with refuse. The Gihon Spring's waters used to flow down the Kidron Valley, until they were diverted to provide water to local communities. Nahal Kidron is flowing again, but this time... with raw sewage. And Jerusalem is once again central to a key environmental issue with serious political ramifications. The beautiful wadi (desert stream) runs from east Jerusalem, where it cuts past the walls of the Old City (and the appropriately named "Dung Gate") and the Mount of Olives, becomes a deep canyon as it whirls eastward through the Judean Desert plateau, passes several Arab localities, and finally gushes into the Dead Sea. But the stream is no longer beautiful, as every single drop of its 28,000 cubic meters (280 million liters) per day is comprised of sewage from Israeli and Palestinian urban areas. The spectacular waterfalls and the rock faces at its end are blackened by the brownish, scum-filled flow. And a few dozen kilometers to the south, tourists bathe in a Dead Sea revered for its skin-enhancing properties. Eighty-five percent of that sewage comes from east Jerusalem, according to the Jerusalem Wastewater and Purification Enterprises, a subsidiary of the Gihon Company (Jerusalem's water company), including Arab and Jewish neighborhoods on the far side of the Green Line, such as East Talpiot and Har Homa. The remaining 15% originates from Bethlehem and Beit Sahur, both cities administered by the Palestinian Authority. And since Israel has annexed east Jerusalem, it is responsible for treating wastewater from this area. A joint Israeli-Palestinian solution has been sought for years, but now Israel is looking for unilateral solutions. "The water divide line causes sewage from west Jerusalem, as well as from the western parts of Bethlehem and Beit Jala, to flow westward to the Soreq water treatment plant," said Adam Schalimtzek, author of a thesis on the topic at the Hebrew University of Jerusalem. "According to the Protocol on Economic Relations of the Oslo Agreements, Israel collects tax money for the PA, and supplies the Palestinians with basic services such as water, electricity and wastewater processing. The costs are then deducted from the amount of money that is finally transferred to the PA," he said. The processed water flows down the Yarkon River to the Mediterranean Sea, or is used for agriculture. "But water from east Jerusalem, between Jerusalem and Jericho, flows straight into the Kidron, without being processed at all," Schalimtzek said. While wastewater from the northern Jerusalem area flows into a pipe along another valley, Nahal Og, to a treatment plant, and then is used to irrigate palm trees and other crops, no such plant exists for the Kidron sewage. As the Kidron flows, evaporation increases the concentration of pollutants that reach the Dead Sea. A good deal of it also seeps through the soil and reaches the underground aquifers, contaminating drinking water reserves. Only during rare winter and spring floods does the Kidron become relatively clean. "This sewage flows there because geography doesn't care about borders and politics," said Shony Goldberger, district manager for the Jerusalem area at the Environment Ministry. The optimal site for a treatment plant is in the PA, beyond the security barrier; for this reason, any plans to build a plant need to be coordinated with the Palestinians, and the results of cooperation so far have been poor, to say the least, he said. "The Germans did try to broker a deal," said Itay Fishhendler, who heads the Environmental Planning Policy and Management Program at the Hebrew University. The $80 million project was to be coordinated between Israel and the Palestinians, but failed due in part to the upkeep costs that would have been generated, which the Palestinians said they could not afford in the long run, and more importantly because "the Palestinians don't want to acknowledge Israeli control of the area," Fishhendler said. "Israelis want quality of life," said Fishhendler, referring to their concern over the environmental and the economic consequences of damaging the land. "Palestinians want life, and this is secondary to them." Still, "if they are to abide by the 'polluter-payer' principle, they should contribute something." Yusef Awayes, an engineer working on the issue for the Palestinian Water Authority (PWA), based in Ramallah, had this to say: "The sewage in Wadi al-Mar [the Arabic name for Nahal Kidron] comes in part from Israeli settlements such as Ma'aleh Adumim, as well as from east Jerusalem, which the Palestinians consider occupied territory. "Building a plant with the Israelis to process that wastewater would mean accepting the de facto rule of Israel over that land, which is a political decision that the PWA cannot endorse. We can discuss the issue on a scientific and environmental level, but this is politics that only the Palestinian political echelon can handle," Awayes said. For the Palestinians, according to Awayes, agreeing to process wastewater produced by Israeli settlements would entail recognition of their legitimacy. Awayes said he regretted that Article 40 of the Oslo Accords, which deals with water-related issues, based all cooperation on "the goodwill of both sides," and didn't set a timetable or stricter guidelines for joint projects. "These are negotiations, and nobody wants to make a genuine effort, but rather [they want] the other side to take a step. Nothing can be achieved without a clear idea of what the final status would look like," he said. While Awayes is fully aware of the environmental disaster unfolding, he said the PA was balancing the cost of major pollution of its aquifers against that of acknowledging Israel's settlement enterprise and conferring upon it a de facto legality. After almost 30 years of pollution in the valley, the Environment Ministry has started to look into alternatives to building a treatment plant downstream, perhaps locating it within the Jerusalem municipal boundaries, or diverting the wastewater to other sewage systems. More than a year ago, said Goldberger, the ministry issued a warning to the Jerusalem Wastewater and Purification Enterprises, threatening them with a lawsuit if no solution was found in the near future to on the issue. Israel Barghil, who runs the project for the Gihon subsidiary, said the delays were due to them "doing their best to reach an agreement with the Palestinians before resorting to unilateral solutions." Earlier this month, the company presented an executive summary to the Prime Minister's Office, suggesting several possible solutions, including diverting all or part of the wastewater flow to the Nahal Og pipe for processing in the existing plant. "But the water wouldn't be available for the irrigation of Palestinian farmlands anymore," said Barghil. One solution entails having the wastewater flow "up," which would require major construction work in urban areas, and would double the original estimate of NIS 100m. for a new treatment plant. The increased costs of whichever solution is chosen will be covered by the state, which would reimburse the water company. Building a plant inside Jerusalem would also double or triple the costs, not to mention the undesirability of having a sewage processing plant next to inhabited areas.