PERMANENT_ID		ID number for each lake that corresponds to high-resolution USGS National Hydrography Dataset
lake.name		name of each lake (standardized across all files)
date			date of measurement in YYYY-MM-DD format
year			year of measurement, four digit format
month			month of measurement, values range 5-9
day			day of measurement, values range 1-31
SO4_minus2		sulfate; mg/L
NO3_minus		nitrate; mg/L
CL			chloride anion; mg/L
Fluor			fluoride anion; mg/L
ANC.ueq.L		acid neutralizing capacity; ueq/L
DIC			dissolved inorganic carbon; mg/L
DOC			dissolved organic carbon; mg/L
SiO2			silica; mg/L
Calcium			calcium; mg/L
Magnesium			magnesium; mg/L
Sodium			sodium; mg/L
Potassium		potassium; mg/L
NH4_plus		ammonium; mg/L
AL_TD.ug.L		total dissolved aluminium; ug/L
AL_TM.ug.L		total monomeric aluminium; ug/L 
AL_OM.ug.L		total organic monomeric aluminium; ug/L
AL_IM.ug.L		total inorganic monomeric aluminium; ug/L
pH.lab			laboratory measured pH
pH			field measured pH
Color.PtCo		water color platinum-cobalt scale 
Conduct.uS.cm		conductivity microsiemens/cm 
			
* unless otherwise stated in the header, units are in mg/L where appropriate.
** all samples were measures in surface water grab samples (0-1.5 m depth)