UPDATE: I dilluted a sample down to 1/4th and arrived at just under 240ppm CYA.

For what it's worth, I also found some old water analysis done by a national chain. They found that CYA was 121 this time last year, and in 2010 it was 161.

Finally, I no longer believe the 30k gallon number (which is from that same shop) is accurate. I think the real number is in the 20-25K gallon range, probably closer to 20K gallons.