WABAG adopts the Hybrid Annuity Model (HAM) for its sewage treatment plant (STP) projects in India, combining government support with private investment to ensure sustainable and reliable services. This model is ideal for addressing long-term operation and maintenance (O&M) needs, ensuring high-quality performance over the lifespan of the project. Approximately 60% of PPP projects in India focus on O&M improvements, making the HAM model particularly effective.

The HAM structure involves the Authority paying 40% to 50% of the capital expenditure (Capex) during the construction period. The remaining Capex, funded by the Concessionaire, is reimbursed over 15 to 20 years through annuities, including interest and O&M service fees. This funding mechanism, supported by Central Government incentives, reduces the financial burden on private entities, making it an attractive option for investors and developers.

WABAG’s extensive experience and significant participation in flagship programs like the Namami Gange Program demonstrate its capability to deliver state-of-the-art STPs under the HAM model. Our breakthrough in HAM projects began in 2018 with the KMDA contract, where we constructed 180 MLD STPs in Kolkata. Subsequent successes included projects with BUIDCo in Patna, Bihar, as part of the Namami Gange program, and a state-funded PPP initiative in Ghaziabad to build a 40 MLD TTRO plant. These projects not only focus on effective sewage treatment but also incorporate facilities for green power generation, enhancing sustainability.

HAM models are also used for PPP projects where the requirement is the production of tertiary treated water (potable water produced from domestic sewage or industrial effluent) to fulfill the needs of industries through a tripartite Concession Agreement between Concessionaire, ULB owning treated sewage and Industries who are end users of treated water. This versatile application of the HAM model highlights WABAG’s adaptability and technical prowess in addressing diverse water treatment challenges.