The City of Havre owns and operates a 4.5-mgd conventional water treatment plant that treats water from the Milk River. The Milk River at Havre can be characterized by large seasonal variations in total suspended solids, color alkalinity, turbidity, and total organic carbon (TOC). Havre selected Carollo to perform an evaluation of the Havre Water Treatment Plant and distribution system and to develop a water master plan to guide Havre in renovating and upgrading the water treatment plant and distribution system. The project was driven by several issues, including the need for renovation and/or replacement of aging plant facilities and distribution system components, additional water treatment capacity to replace poor quality well water, and positioning Havre’s facilities for compliance with upcoming water quality regulations.

The project team began work with an onsite treatability study during an episode of high color and turbidity caused by spring runoff. Other project tasks included:

• Regulatory analysis.
• A pretreatment evaluation of chemical mixing efficiency, application sequence, location, doses, and storage facilities.
• A comprehensive facility evaluation of key water treatment plant process components and support facilities (e.g., HVAC, lab, administrative needs, instrumentation, and control).
• A capacity analysis involving desktop and computer simulation methods to establish the water treatment plant process and hydraulic capacity.
• Development of alternatives and cost estimates for renovating and upgrading the existing facilities.
• Development of a hydraulic simulation model (Cybernet®) of the existing distribution and storage systems.
• Presentation and discussion of the study findings with staff in several interactive workshop sessions.
• Development of a master plan for renovations and upgrades to the Havre water supply system, complete with a CIP for scheduling the improvements.