Status: 

Ongoing

Title

Chemistry of stream water from the Luquillo Mountains
Summary

Short name: 

LUQMetadata20

Data set ID: 

20

Abstract: 

Stream water is collected weekly at the Luquillo Mountain sites listed below. These data sets begin as early as 1983; LTER sampling began in 1988.

Stream water samples are grab samples taken from the water/air interface at stream channel center on the sampling day (usually Tuesdays). A continuous record of stream stage (height) is recorded by a datalogger at all ongoing stream sampling sites. Average daily streamflows are available from the USGS and at other locations (Hydrology and Meteorology) on this site.

All samples are measured for pH and conductivity, and then filtered (pre-combusted Whatman GF/F glass fiber filter) prior to further analysis. From 1983-1994 samples were cooled and returned to the San Juan chemistry laboratory for analysis. During those years, samples for NH4 and NO3 analyses were refrigerated continuously until analysis. Subsamples for NH4 analysis were also preserved with 1 molar H2SO4. From 1994 on, samples for NH4 and NO3were frozen until analysis, were not acidified, and all analyses were conducted at the University of New Hampshire.

Stream water Sampling Sites
Descriptions of LTER LUQ stream water weekly sample chemistry data from 1988 onwards. Chemical concentrations are recorded as mg/L or mg/L as appropriate. Values below detection limits are recorded as 1/2 the detection limit. 

Site

Abbreviation

Description Comments

Quebrada Sonadora

QS

El Verde stream.

 

Quebrada Toronja

QT = QT1

El Verde stream.

 
Rio Espiritu Santo

RES4

LEF North Stream

LEF= Luquillo Experimental Forest

Quebrada Prieta A

QPA

El Verde stream

 

Quebrada Prieta B

QPB

El Verde stream

 

Quebrada Prieta

QP

El Verde stream

 

Puente Roto Mameyes

MPR

Bisley stream

Previously "PRM"

Quebrada uno-Bisley

Q1 .

Bisley stream

 

Quebrada dos-Bisley

Q2 

Bisley stream

 
Quebrada tres-Bisley

Q3 .

Bisley stream

 

Rio Mameyes Gage 

MG

Bisley stream

 

Rio Icacos

RI

LEF South stream

 

Rio Sabana

RS

LEF West stream  

Quebrada Guaba

QG

Icacois stream  
Dates
Date Range: 
1983-05-24 00:00:00 to 2016-12-27 00:00:00

Publication Date: 

2011-04-11 00:00:00
People

Owner/Creator: 

Contact: 

Additional Project roles: 

Name: Eda Melendez-Colom Role: Data Manager
Name: Douglas A. Schaefer Role: Associated Researcher
Name: Frederick Scatena (In Memorium) Role: Associated Researcher
Methodology

Methods: 

Analytical Techniques
pH - Electrometric with combination electrode
Conductivity - Conductivity bridge
Cl - up to 1989 by automated colorimetric analysis (thiocyanate); after 1989 by liquid chromatography with conductivity detection
NO3-N - up to 1989 by automated colorimetric analysis (Cd-Cu reduction); after 1989 by liquid chromatography with UV or conductivity detection
SO4-S - Liquid chromatography, conductivity detection
Na, K, Mg, and Ca - up to 1994 by atomic absorption spectroscopy; after 1994 by ion chromatography with conductivity detection
NH4-N - automated colorimetric analysis (phenolhypochlorite)
PO4-P - automated colorimetric analysis (molybdate blue)
DOC - up to 1998 by persulfate oxidation (McDowell et al. 1987); after 1998 by high temperature catalytic oxidation
TDN - prior to 1998 by persulfate oxidation and automated colorimetric analysis; after 1998 by high temperature catalytic oxidation with chemiluminescent detection
TDP - by persulfate digestion followed by automated colorimetric analysis
SiO2 - automated colorimetric analysis (molybdate blue)

Table 1. Data Abbreviations, Detection Limits, and Units of Measure

Datum

Abbreviation

Detection limit

Units

pH

pH

pH units 

Conductivity 

Cond

micromho/cm 

Chloride 

Cl

0.1

mg/L 

Nitrate 

NO3-N 

3-10

mg N/L 

Sulfate 

SO4-S

0.1

mg S/L

Sodium 

Na 

0.1

mg/L

Potassium

K

0.05

mg/L 

Magnesium 

Mg 

0.1

mg/L  

Calcium 

Ca 

0.1

mg/L

Ammonium 

NH4-N 

2-10

mg N/L 

Soluble Reactive Phosphate

PO4-P

3

mg P/L

Dissolved Organic Carbon

DOC

0.1

mg/L

Total Dissolved Nitrogen

TDN

0.1

mg/L

Total Dissolved Phosphorus

TDP

3

mg/L

Silica

SiO2

0.1

mg/L as SiO2

Instrumentation: 

Electrometric with combination electrode

Conductivity bridge

liquid chromatography with conductivity detection

liquid chromatography with UV or conductivity detection

Liquid chromatography, conductivity detection

ion chromatography with conductivity detection

automated colorimetric analysis (phenolhypochlorite)

automated colorimetric analysis (molybdate blue)

high temperature catalytic oxidation

high temperature catalytic oxidation with chemiluminescent detection

persulfate digestion

Additional information: 

In this new LUQ website-IM system, this data set was was split into two data sets, separating the chemistry data from rain and throughfall collectors into LUQMetadata 174: Chemistry of rainfall and throughfall from El Verde and Bisley.

Status: 

Ongoing

Time Period: 

Long-Term
Categories

EML is valid: 

Yes