Certified Instrument Specialist (CIS) Practice Exam 2026 - Free CIS Practice Questions and Study Guide

High conductivity in water is primarily an indicator of the presence of dissolved ions, which are often salts. Conductivity measures the ability of water to conduct electricity, and this ability increases as the concentration of dissolved ions rises. Salts, such as sodium chloride, dissociate into ions in water, leading to a significant increase in conductivity. Therefore, when water exhibits high conductivity, it generally means there are high amounts of dissolved salts or other ionic substances present.

In this context, low salt concentration would result in lower conductivity, clean water quality is typically associated with low conductivity due to the absence of ions, and high acidity is not directly linked to conductivity levels as it depends on hydrogen ion concentration rather than the presence of a range of ions found in salts. Thus, high amounts of salt are rightly identified as the cause of high conductivity in water.