Lake Armstrong

Lake Armstrong (Snohomish County) is a 30 acre lake north of Arlington, WA. Although the lake’s nearly 370 acre watershed is mostly undeveloped, Lake Armstrong experiences occasional blue-green algae blooms that may produce toxins. Avoid water contact if there are warning signs posted. Lake Armstrong drains into Armstrong Creek, which in turn discharges into the Stillaguamish River.

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LakeKeyDateDO mg/LTemp CpHCond uS/cmChl ug/LAlk mg/LTurb NTUNH3 ug-N/LTN ug-N/LNO2+3 ug-N/LTP ug-P/LSRP ug-P/L
ArmstrongARM8/31/099.820.67.767.< 10520< 1016.98.2
ArmstrongARM6/23/109.0820.27.753.23.321.10.58< 10480< 1025.312.1
ArmstrongARM7/25/118.621.27.755.< 1023.69.5
ArmstrongARM7/15/138.7822.97.461.14.724.51.32< 10430.2< 1015.7< 3
ArmstrongARM7/28/148.523.57.5622.1324.80.4727.548416.415.9< 3
ArmstrongARM7/20/158.1727.47.766.8NA270.37< 10428< 1014.3< 3
ArmstrongARM7/18/168.3822.< 1021.1< 3
ArmstrongARM7/19/178.6923.17.5612.523.80.555< 10362.8< 1012.2< 3
ArmstrongARM7/18/< 1039013.414.1< 3