The following is a water quality report from Oct. 6 to Nov. 6 compiled from data courtesy of Heal the Bay, a nonprofit environmental group.
Grades are based on an A+ to F scale. Grades indicate the likelihood of swimmers becoming ill. Water samples are analyzed for bacteria – enterococcus, total and fecal coliforms. The report does not measure the amount of trash or toxins found at local beaches.
Please note: The last sampling date was Wednesday, therefore beach grades do not reflect the rain that hit the L.A. area on Thursday. However, this week's rain was not significant enough to count for "wet days" at the beach, according to Heal the Bay.
Dark Blue Marker = A+
Light Blue Marker = A
Green Marker = B
Yellow Marker = C
Pink = D
Red Marker = F
The "last updated" bit that appears when you click on the marker is when the marker on this map was last updated (ie. the color changed), not when the last sample was collected. If the beach's grade hasn't changed in the last three weeks, the marker itself probably will not be updated, as the grade and the color will remain the same. For example—the Redondo Municipal Pier marker on the map was updated 23 hours ago, but according to the note in the article, the sample was taken Wednesday. Patch updates its markers on Friday afternoons/evenings. This is a process that involves manually changing the color of the marker. Unfortunately, I don't believe we can take the "last updated" bit off the markers—it's something that Google Maps automatically generates. I hope this clears some of the confusion!
You need to look at the source, which is the HTB web site. I appreciate Patch trying to help spread this data, but it is not always exactly a perfect electronic rendering. Maybe Patch could so somehow embed the HTB results in the patch page? Jonathan (below) sheds some light on the confusion.