In response to customer concerns about water quality, particularly hardness levels, Valley Water Systems (VWS) engaged the firm of Tighe & Bond to study the problem and evaluate alternatives to reduce hardness. The Tighe & Bond study looked at various options to reduce hardness in the system. The hardness comes from naturally occurring mineral deposits (primarily calcium) in the aquifers at Johnson Ave. and Woodford Ave. The Woodford Ave. source is the most problematic with regard to hardness and customer complaints. The study considered alternatives to reduce hardness to levels below 150 ppm throughout the system. Although there are no regulatory limits for hardness, and the available literature suggests that there is no specific target level for eliminating customer complaints, this was considered to be a reasonable level based on general guidelines and published information relative to customers’ sensitivity to hardness. Below is the Executive Summary and full study provided by Tighe & Bond.