Evaluation of Travilah Quarry for Water Supply Storage
Interstate Commission on the Potomac River Basin
Black & Veatch was retained by the Interstate Commission on the Potomac River Basin to perform the feasibility study of potential prerequisites for use of the Travilah Quarry as a raw water supply storage facility, to supplement the existing water supply for the Washington Suburban Sanitary Commission and the Washington Aqueduct.
The assessment was divided into two phases.
The first phase of the study focused on studying characteristics of the quarry for water storage potential and water quality aspects. The findings deemed the quarry suitable for the purposes of raw water storage and presented estimated storage volumes.
The following were the key findings of the first phase:
- The current storage available in the Quarry is approximately 7.3 BG, based on the quarry reservoir pool elevation of 350 feet above the mean sea level
- The estimated ultimate storage in the Quarry is approximately 17.4 BG, based on the mining plans and quarry reservoir pool elevation of 350 feet above the mean sea level. The ultimate capacity is expected to be available sometime around 2060
- Based on the field reconnaissance and assessment of geology, it was noted that the quarry walls are generally stable. There are natural discontinuities in the rock that may require grouting
- It is expected that groundwater infiltration will be minimal, and hence the resulting quality of stored water will be in the range of available water treatment technologies
- External pumping will be needed to fill the quarry. The management of water quality can be accomplished through inlet/outlet design and pumping strategies
The second phase assessed potential options for conveyance, pumping and presents life cycle costs for different alternatives. It includes a conceptual design and layout of the infrastructure necessary to convey water from the quarry and plant to the Washington Aqueduct.