Ash Pond Redevelopment & Water Recovery System

Make the ash pond's water an asset the plant can recover, not an inconvenience it has to manage.

R.K.M. Powergen Pvt. Ltd. engaged Geotech Design Consultants to assess the feasibility of redeveloping the existing ash pond at its Kharsia plant and to develop an appropriate engineering solution for an associated water recovery system.

The existing ash pond infrastructure needed to manage pond water more effectively and allow it to be drawn off, clarified and returned to the plant in a controlled way. In practice that meant one core requirement: a technically sound arrangement for decanting and settling of pond water, followed by pumping and reuse of the recovered water in the plant process.

Geotech Design Consultants carried out the feasibility assessment, evaluated the site as it actually stood, and developed a technical solution shaped by the operational, civil, hydraulic, geotechnical and environmental requirements of a live power plant facility.

Detailed as-built drawings of the ash pond and its associated infrastructure were not available. The existing condition therefore had to be established from physical assessment of the site, whatever plant information could be gathered, and engineering evaluation of what was found — not from records.

The pond also lacked a properly developed decant well, which limited any controlled withdrawal or recovery of water. Just as importantly, the existing surface arrangement did not reliably move water towards a single collection point, so a workable water flow and slope arrangement had to be established before any recovery system could function.

The project therefore called for a decant well and settling tank system together with a pumping arrangement capable of transferring settled water back to the plant for beneficial reuse.

The redevelopment concept introduced a proper decant well and settling tank arrangement for controlled collection and clarification of ash pond water, connected by a deliberately designed hydraulic path from the pond to the decanting facility. Settling allows suspended solids to drop out before the recovered water is drawn into the pumping system. A dedicated pump house and pumping arrangement then conveys the clarified water back to the power plant, where it re-enters the process.

The civil and hydraulic arrangement was developed against existing ground levels, available space, operating water levels, access requirements and constructability — a practical system that could actually be built within the footprint of the existing facility.

1. 01Ash PondSOURCE
2. 02Decant WellCONTROLLED DRAW-OFF
3. 03Settling TankCLARIFICATION
4. 04Pump HouseRECOVERY PUMPING
5. 05PlantPROCESS REUSE

Fig. 1 — Recovery circuit: Pond → Decant Well → Settling Tank → Pump House → Plant Process

The study did not stop at a concept. Geotech Design Consultants assessed what implementation would actually require and developed the engineering approach for the facility accordingly.

Design and drawing development covered the existing ash pond configuration, hydraulic levels, the proposed water flow path, the decant well, the settling tank, the pump house and the associated civil infrastructure. Where drawings did not exist, the solution was built on site observation, available plant information and engineering assessment — then coordinated so that the civil, hydraulic, electrical and operational elements work together as one integrated system rather than as separate packages.

The central outcome of the redevelopment is a controlled mechanism for recovering and reusing ash pond water inside the plant.

On completion and commissioning, pond water is routed through the decanting and settling system and pumped back to the plant. The facility gained better control of its water balance, reduced wastage, and a higher share of internal reuse of water already on site — an operational improvement and an environmental one, aligned with water conservation and recycling within thermal power operations.

Geotech Design Consultants delivered the feasibility assessment, engineering evaluation and technical design support for the redevelopment of the existing ash pond facility, introducing a proper decant well, settling tank and pumping arrangement together with the civil infrastructure required for controlled water recovery.

Despite the absence of existing drawings and the challenges of hydraulic slope management, pump house construction and electrical connectivity at a live plant, the facility was successfully developed and implemented in accordance with applicable standard engineering practice and environmental considerations.

This project demonstrates our capability to assess existing industrial infrastructure, identify the engineering constraints that come with it, and develop solutions that can actually be implemented — combining feasibility assessment, site-based engineering judgement, hydraulic and civil design, constructability thinking and environmental responsibility to meet the client's operational requirements.

• 01

  Feasibility studies for brownfield industrial facilities

• 02

  Geotechnical and civil engineering assessment

• 03

  Hydraulic and water management design

• 04

  Ash pond, decanting and settling systems

• 05

  Pump house and allied civil structures

• 06

  Design, drawing and implementation support