Jordan’s Shallala Upgrade Links Peak-Flow Treatment to Irrigation Reuse

At northern Jordan’s Shallala plant, the toughest test comes when the incoming flow peaks. The European Bank for Reconstruction and Development says the aging plant is overloaded by both the volume of wastewater it receives and the amount of organic matter it must treat. The bank approved a sovereign loan of up to US$55 million on November 4 to help rehabilitate and expand the facility for the Water Authority of Jordan. The project aims to make treated water consistently suitable for agricultural reuse. The Shallala wastewater treatment upgrade must address both kinds of overload.

Two Kinds of Overload

Wastewater volume and the amount of material it carries place different demands on the plant. A surge in volume can shorten the time available for treatment or stretch the equipment that moves and separates water and solids. A higher organic load puts more demand on the processes that break that material down. On a difficult day the plant can face both pressures at once. The bank links that existing combination to uneven performance against Jordan’s discharge and reuse standards.

The expansion sets an ultimate average capacity of about 30,500 cubic meters per day. It also aims to raise capacity to around 240,000 population equivalents, a way to express the organic load the plant is designed to handle. Each figure answers a different question. Checking performance during peak flow alongside those design measures will show whether the treatment process can maintain water quality when inflow varies.

Keeping Treatment Running During the Work

The project stays within the existing plant footprint. The design calls for continuous treatment during rehabilitation, alongside changes to inlet screening, sludge handling and odor control. Working inside an operating plant makes the order of construction important. Operators need to know what treatment capacity is available while equipment or individual parts of the process are being worked on.

A work schedule can show when equipment is expected to come out of service. The operating plan has to account for how the rest of the plant will handle the wastewater arriving during that interval. Construction and treatment therefore share a constraint. A step that looks straightforward on the contractor’s schedule may need to be timed around the plant’s available capacity and the risks of an unusually heavy inflow. The project’s environmental action plan also assigns monitoring duties during construction. The contractor must document performance and mitigation, with review by the project implementation unit and the owner’s engineer. Yarmouk Water Company already operates the site, so the project will add construction oversight alongside an existing operating responsibility.

Why Reuse Depends on Operating Records

The expected agricultural benefit follows from treating wastewater to the applicable standard with sufficient consistency. An average daily treatment figure describes volume across time. Farmers and the institutions managing reuse need confidence in the quality of the water actually supplied. Periods of poor effluent quality can interrupt that supply or limit where it can be used.

The bank plans to support the Yarmouk Water Company in monitoring infrastructure performance. For reuse, that monitoring can connect inflow conditions, treatment performance and the quality of water leaving the plant. Comparing those records over time can show whether the rehabilitation improved performance under conditions that previously caused difficulties. The design targets describe the intended result. An operating record would establish how consistently the plant achieves it. A reuse assessment can also distinguish how frequently the plant meets the standard from how far it misses it when it does fall short. Those observations would help explain whether an interruption reflects the occasional failure of a component or a pattern under heavy load.

What Sludge Handling Contributes

The scope also includes restoring anaerobic digestion and combined heat and power. Digestion uses microorganisms to break down sludge in the absence of oxygen. The resulting biogas can supply equipment that produces electricity and recoverable heat. Those gains depend on a plant being able to collect and handle sludge consistently and operate the associated equipment.

Sludge handling matters to treatment reliability in its own right. A plant needs to manage the solids it separates from wastewater day after day. Rehabilitating that part of the process alongside the liquid treatment equipment makes it possible to address the waste stream while pursuing energy savings. The funding documents describe both as intended gains. Operating data will show how the restored equipment performs in practice.

How the Financing Connects to Delivery

The bank lists an overall project cost of about US$68.3 million and expects a donor grant to contribute. It also describes support with tender preparation, construction supervision and performance monitoring. Those steps connect a financing approval to work inside a live wastewater plant, where the timing of works and the condition of the existing equipment affect how the upgrade can proceed.

Once the plant is running at its intended capacity, an important question will be how its effluent behaves on the days that used to expose the overload. Reuse can contribute to water security when the quality of that supply is dependable enough for agricultural users to plan around it. Demonstrating that reliability is where the work at the inlet, in treatment and in the operating records comes together.