Sewage treatment MAVTI, Jerusalem | AM•GAR

Client:	MAVTI
Location:	Jerusalem
Architect:	Mike Turner
Engineer systems:	Lavi | Nativ
Engineer treatment:	Technological Conservation & Environment
Completion:	Ongoing

All cities in Israel, except Jerusalem, are connected to a regional system of collection and treatment of waste water. Each region is a legal entity with an administrative structure, empowered to plan, finance, collect fees and implement projects. Jerusalem, on the other hand, requires its own organization, as part of its mandate falls within the administered territories. Since collection of waste water is gravitational, part of Jerusalem's waste flows to the west, and the coastal plain, and part flows to the east and the Dead Sea. To provide the administrative structure for waste water, the Jerusalem water distributor Gihon, created a separate company MAVTI to provide solutions for waste water management.

The Firm was appointed by MAVTI as the project manager for all waste water planning, and development.

Jerusalem essentially has two drainage systems, waste and storm drainage that flows to the east, will find its way to Nahal Soreq, and Nahal Refaim (a tributary of the Soreq), which flows to the Mediterranean. At the head waters MAVTI has constructed secondary waste treatment centers that provide recycled water for tree agriculture, such as dates and olive. There are currently plans to upgrade the treatment facilities for tertiary treatment suitable for all agricultural cash crops. (drinking water quality) according to recent State legislation.

The second drainage system flows to the east by way of the Kidron Valley (by the Historic biblical City) and the Og Valley (to the north of the Kidron). A major secondary treatment facility has recently been completed at Nebi Musa (between Jerusalem and Jericho). This facility can provide agricultural water to the settlements in the Jericho area. Currently in the planning stage is the upgrade of this treatment facility to tertiary capacity suitable for all crops.

The problematic drainage valley is the Kidron which serve the majority of east Jerusalem (east of the water shed line, not the political definition), and a significant population of just half a million (2010). Currently there is no secondary treatment facility which would be by necessity located in the Administrative Territories. The planning and construction has been held up by political jurisdictions as defined under the "Oslo Accords (Area A, B, C with Area A under complete Palestinian Authority Control). From a purely engineering point of view, the location of the treatment center would be in area C, but a short portion of the collection systems would pass through area A. Despite agreements that he waste water from the treatment facility could be used by the Palestinian Authority, to date permission to cross area A has not been given.

There are four options that are technically feasible but very expensive:

• Tunnel 3km long under area A – The political ramifications of tunneling under area A may render this option practical but not feasible.
• Pump to Nahal Og & expand Og treatment plant – This would require a lift head or 300m to pump from one valley to another. There are installations in America with this vertical lift, and such systems are feasible, but the energy (electrical) required to pump is substantial, and the environmental implications are significant. The Og treatment plant can be expanded incrementally.
• Locate a treatment facility in the Kidron Valley – The treatment facility would have to be located close to the Old city and besides this physical limitation that would make construction almost impossible, the environmental requirements in a populated area would preclude development.
• Pump to Nahal Refaim & expand Soreq treatment plant – This is similar to pumping to Nahal Og, but the lift is higher and the energy cost greater. The Soreq treatment plant can easily expand to accommodate the additional effluent.

A decision will be made shortly and will supply additional irrigation for agriculture.