Conversion Factors, Datums, and Abbreviations


Conversion Factors


Inch/Pound to SI


Multiply	By	To obtain
inch (in.)	2.54	centimeter (cm)
acre	4,047	square meter (m2)
square mile (mi2)	259.0	hectare (ha)
square mile (mi2)	2.590	square kilometer (km2)
cubic foot per second (ft3/s)	0.02832	cubic meter per second (m3/s)
million gallons per day (Mgal/d)	0.04381	cubic meter per second (m3/s)
grams (g)	0.035274	ounce, avoirdupois (oz)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:


°F=(1.8×°C)+32


Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25°C).


Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or micrograms per liter (µg/L).


Turbidity values in water are given either in formazin nephelometric units (FNUs) or nephelometric turbidity units (NTUs). 


Ultraviolet-light absorbance is measured in nanometers.


Datums


Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88).


Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).


Abbreviations


Alum	Aluminum sulfate
ACH	Aluminum chlorhydrate
BQ	Benchmark quotient
CRW	Clackamas River Water
DBP	Disinfection by-product
DBPFP	Disinfection by-product formation potential
DHBA	3,5-dihydroxy-benzoic acid
DO	Dissolved oxygen
DOC	Dissolved organic carbon
DOM	Dissolved organic matter
DWTP	Drinking-water treatment plant
ex	Excitation
em	Emission
FDOM	Fluorescent dissolved organic matter
FI	Fluorescence index
HAA	Haloacetic acid
HAA5	Total of five haloacetic acids
HAAFP	Haloacetic acid formation potentials
HIX	Humic index
LED	Light-emitting diode
LO	City of Lake Oswego
MCL	Maximum contaminant level
NMDS	Nonmetric dimensional scaling ordination
NWQL	U.S. Geological Survey National Water-Quality Laboratory
PAC	Powdered activated carbon
PCA	Principal Component Analysis
QA	Quality assurance
rpm	Revolutions per minute
S	Spectral slope
SR	Spectral slope ratio
SRM	Standard reference material
SHAAFP	Specific formation potential for haloacetic acids
STHMFP	Specific formation potential for trihalomethanes
SUVA	Specific ultraviolet absorbance
THM	Trihalomethane
THM4	Total of four trihalomethanes
THMFP	Trihalomethane formation potential
TOC	Total organic carbon
TP	Total phosphorus
TPC	Total particulate carbon
TPN	Total particulate nitrogen
USEPA	U.S. Environmental Protection Agency
USGS	U.S. Geological Survey
UVA	Ultraviolet absorbance
UVA254	Ultraviolet absorbance at 254 nanometers
VOC	Volatile organic compounds

First posted February 11, 2013