Online Links:
File comment HeeiaCN1202-0403.xls Combined Nitrogen HeeiaLead0303-1103.xls Total Lead HeeiaTN1202-0403.xls Total Nitrogen HeeiaTP1202-0403.xls Total Phosphorous
Sample dates, locations, and units are defined in each file Redundant ASCII copies were made of each with same file name except for a CSV (Comma Separated Version) extention.
The following were downloaded off the internet, http://www.wcc.hawaii.edu/water/
Directory ../../data/figs_text The following files contain plots and a table of the data found in the Excel files described above:
combined_nitrogen_plot_table.gif total_phosphorous_plot_table.gif lead_plot_table.gif totalnitrogen_plot_table.gif
These files have descriptions and comments regarding each parameter:
combined_nitrogen_discussion.txt total_phosphorous_discussion.txt lead_discussion.txt totalnitrogen_discussion.txt
More information regarding the data collection locations can be found in directory ../../data/sites:
Figures depicting location: HeeiaSiteMap.jpg HeeiaSite01.jpg HeeiaSite02.jpg HeeiaSite03.jpg HeeiaSite04.jpg HeeiaSite05.jpg HeeiaSite06.jpg HeeiaSite07.jpg HeeiaSite08.jpg
Descriptive text and discussion: HeeiaSite01.txt HeeiaSite02.txt HeeiaSite03.txt HeeiaSite04.txt HeeiaSite05.txt HeeiaSite06.txt HeeiaSite07.txt HeeiaSite08.txt
National Oceanic and Atmospheric Administration, Windward Community College
Assess the water quality of Heeia Stream and adjacent bay waters.
Summary of Method. Water samples are filtered and analyzed by ion chromatography (IC). Each analytical batch consists of a blank, 5 external calibration standards and a calibration check for every 8 samples. The method detection limits (MDL) are as follows: 0.1 mg/L for phosphate, and 0.05 mg/L for nitrite and nitrate.
Preparation of IC samples. Water samples are pre-filtered before analysis in the Dionex ICS-90 ion chromatography system. Fresh water samples (5 mL) are filtered through 0.20 mm IC Millex syringe filters (for freshwater samples) while saltwater samples are filtered through the Dionex Ag/H cartridges and diluted 50:50 using deionized distilled water.
Preparation of IC calibration standards. The following calibration standards are prepared. (1) 0.1 mg/L of phosphate, 0.05 mg/L of nitrite and 0.05 mg/L nitrate (2) 0.2 mg/L phosphate and 0.1 mg/L nitrite and 0.1 mg/L nitrate (3) 1.0 mg/L phosphate and 0.5 mg/L nitrite and 0.5 mg/L nitrate (4) 2.0 mg/L phosphate and 1.0 mg/L nitrite and 1.0 mg/L nitrate (5) 10.0 mg/L phosphate and 5.0 mg/L nitrite and 5.0 mg/L nitrate
Calibration. The calibration curve must consist of at least three data points. The response of each calibrator must be within 10%, otherwise, it does not meet method criteria and must be removed from the working calibration curve.
Final data are summarized in Excel worksheets. The nitrite as N (mg/L) is calculated by multiplying the nitrite (mg/L) with 0.304 (factor). Likewise, the nitrate as N (mg/L) content is calculated by multiplying the nitrate (mg/L) content with 0.226 (factor). The phosphate (mg/L) content is converted to phosphorus (mg/L) by using the factor of 0.326.
Determination of Total Nitrogen and Total Phosphorus
Summary of Method. To analyze the total N and total P content, all phosphorus-and nitrogen-containing substances in the water sample are first converted to inorganic nitrates and phosphates by photo-oxidation. After photo-oxidation, the samples are analyzed as described above.
Photo-oxidation. Water samples (100 mL) added with 2 drops of 30% H2O2, are
photo-oxidized using Ace-Hanovia photooxidation apparatus (Department of
Health State Laboratory) for four (4) hours to hydrolyze all
phosphorus-containing substances into phosphates, and all
nitrogen-containing substances into nitrates.
Person who carried out this activity:
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints: Dataset credit required
NOAA makes no warranty regarding these data,expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA, NESDIS, NODC and NCDDC cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.