Is that water safe to drink? Can I go swimming in that lake? How come there are no fish living in that river??? The answer to these questions has to do in part with the quality of the water.

When we talk about water quality, we're talking about more than whether or not the water is polluted. Scientists are also interested in the temperature, the amount of dissolved oxygen, the turbidity (amount of suspended solids), the pH (a measure of how acidic or basic something is) and the salinity of the water.

Science policy issues centered on the management and protection of global water supplies attracted international attention in 2003, the United Nations' Year of Freshwater. Water quality testing is an important part of the mission of Pier Wisconsin and the shipboard activity of the Denis Sullivan. The need to broaden the involvement of community stakeholders and citizens in addressing freshwater issues is critical to sustaining life on earth.

There are many physical, chemical and biological parameters, or measures, that can be monitored to find out if water is suitable for drinking, swimming or supporting wildlife.

Our crew regularly measures two physical and three chemical parameters of water from the S/V Denis Sullivan. These are:

Physical Parameters:

• Temperature
• Turbidity

• Dissolved oxygen (DO)
• pH
• Salinity

We collect our data with permanently installed sondes (which are very accurate) and with field instruments (which are somewhat less accurate but easier to use because they are portable). You can take a look at the results on our online Data page.

Written by Norma L. Renner for Pier Wisconsin