RESULTS OF PAST SEMESTER TAP WATER MEASUREMENTS - Updated for selected semesters of student work up to Fall, 2011

Finding your latitude and longitude:
1) Use Google Earth.  Download the program.  Then type in your address.  Google Earth will find your address on a map.  If you move the mouse over the spot representing your address on the map, the latitude and longitude will be given at the bottom of the window.  The program takes a fair amount of memory so you might want to investigate other methods of getting latitude and longitude.

2)  Use this site and enter your address.  It should return the latitude and longitude.

3) Use a GPS device (you may have one in your phone).

Students were asked to bring in a tap water sample from their homes to analyze for Mg and Ca, two of the main components leading to "hard" water.  The purpose of this study was to give students experience in analyzing real samples and to determine which areas around Sacramento had "soft" or "hard" water.

Summary of Results:
Students have brought in tap water samples from their homes, have analyzed the samples, and and have reported the results.  The data shown are for past semesters but not over the last year.  To improve the data quality, a number of quality control (QC) criteria were used to discard suspect data.  These criteria are listed in the data table.  Only a fraction of the data generally meet the QC criteria.  Note that not all of the data quality issues have been addressed.  There may have been sampling errors (e.g. collection of water from a tap with a water softener) or mistakes in dilution or calculations. There also may be seasonal changes in concentrations or changes from one year to another.

A summary data table is presented below showing average values within each catagory.  Additionally two "maps" are given showing the distribution of Mg and Ca concentrations (I hope to improve the quality of the maps in the future).

Most of the water in the Sacramento region either comes from local ground water sources or from local river sources (mainly the American River for most of the samples).  The data table showed that water samples from the Sacramento Region to be softer on average than from surrounding areas (such as Davis and Yuba City). However, the map values do show water from foothill towns (Folsom and Cameron Park) to have soft water.  Within the Sacramento region, water was found to be soft near campus on the south side of the American River, while being the hardest close to CSUS but on the north side of the American River.  Most of the samples with higher Mg and Ca concentrations likely originate from ground water, while many of the softer water samples from Sacramento originate from the American River.  For groundwater samples, although variability exists, water samples in locations near rivers (e.g. the American River) generally have lower concentrations than samples located farther from Rivers

Data Table

Ca Map

Mg Map
(Appologies for "ugly" maps)

Note: You can calculate the water hardness (ppm CaCO3) by taking converting ppm Mg to ppm CaCO3 and ppm Ca to ppm CaCO3 and summing these two.

You also may be able to find information about Mg and Ca concentrations from many local water agencies. You can often find these by finding the agency's website and looking for water quality information. As an example, you can find information for portions of the Arden-Arcade region by googling Sacramento Suburban Water District (SSWD) - website link, and then locate their water quality reports (see the 2009 report here: These agencies may indicate if they add F to water.
 Updated 10/11/12