Fort Collins, CO, USA, from the "Fort Collins
Utilities
Drinking Water Quality Report", we have:
nitrate, ppm:
MCL: 10
MCLG: 10
Highest level detected: 0.138
Range: 0.13-0.138
Meets standard: Yes
Typical source: Runoff from fertilizer use;
septic tank leachate
So, we're a little higher than you (10 instead of 9),
but this is largely an agricultural region. And, it's
offset by the fact that we have very soft water, so
I have no trouble growing most any plants, as long
as I provide adequate lighting (I never could keep
mollies, though).