The State of Hawai`i Department of Health (DOH), Clean Water Branch (CWB) data portal provides access to water quality data collected since December of 2004. Data collected prior to that are available from the United States Environmental Protection Agency STORET Data Warehouse. Listed below are the specific date ranges for the various data used in this study. Notice the multi-year gap in data from 1998 to 2004. Presumably, no data exists for this time period or it would have been available from either or both government data portals.

If you would like more information about the sites used for collecting water quality samples, visit the sample sites page. Look up the site of interest using the Station Number or Site Name. Not all sites are listed or have additional data, but those that do often have written descriptions, hand-drawn maps, and photos of the collection locations.

The data can be viewed on the CWB data access web portal.

Turbidity and Microbial data downloaded from CWB Water Quality Data Microbiology download page.

12/27/2004 2/10/2016 11702 rows of data

TN, TP, NO3+NO2, NH4, Chlorophyll a data downloaded from CWB Water Quality Data Chemistry download page.

8/14/2006 2/10/2016 820 rows of data

The United States Environmental Protection Agency STORET Data Warehouse

1/8/1973 12/15/1998 7234 rows of data


Name Changes in the dataset (685, 713, and 724 had spelling corrected).

From To
651 Hale Onoloa Condominium Shore 651 Hale Onoloa Condo Shore
655 Kaa Shoreline, Paia 655 Ka`a Shoreline, Pa`ia
659 Maalaea Small Boat Harbor 659 Ma`alaea Harbor
660 Mahinahina Condominium Shoreline 660 Mahinahina Condo
664 Paia Outfall, Shoreline 664 Pa`ia Outfall, Shoreline
666 Sheraton Kaanapali Shoreline 666 Sheraton Ka`anapali
668 Waihee Farm Shoreline 668 Waihe`e Farm Shoreline
675 Waiopai 675 Wai`opai
681 Kamaole Beach #1 681 Kama`ole Beach #1
682 Kamaole Beach #2 682 Kama`ole Beach #2
683 Kamaole Beach #3 683 Kama`ole Beach #3
685 Keawekapu Beach 685 Keawakapu Beach
687 Maalaea Condos 687 Ma`alaea Condos
688 Hookipa Beach Park 688 Ho`okipa Beach Park
692 Kaopala Bay 692 Ka`opala Bay
693 Hanakaoo 693 Hanaka`o`o
696 Puunoa (Baby) Beach 696 Pu`unoa (Baby) Beach
699 Kuau (Beach Access 402) 699 Ku`au (Beach Access 402)
702 Mai Ponia Oe Iau (Windsurfer) 702 Mai Poina ‘Oe Ia’u
713 Waipulani 713 Waipu`ilani
716 Poolenalena 716 Po`olenalena
719 Oneuli 719 One`uli
720 Puu Olai (Small Beach) 720 Pu`u Ola`i (Small Beach)
721 Mokuleia 721 Mokule`ia
724 Pohaku 724 Pohaki Park
729 Waianapanapa 729 Wai`anapanapa
733 Kahekili/Airport 2 733 Kahekili / Airport 2

There were some obviously erroneous latitude and longitude coordinates, which we corrected. Note that the actual collection point may be many meters away along the beach or shoreline from where the marker displays. Other coordinates in the original data may also be suspect, indicating a shoreline parking place for example, so please contact the Clean Water Branch if greater accuracy is required. Their Sample Sites web portal has photos and hand-drawn maps of most collection sites.

Original bad latitude, longitude coordinates.
706 Harbor Lights 20.87778 -156.476
655 Ka`a Shoreline, Pa`ia 20.89114 -156.471
729 Wai`anapanapa 20.75583 -156.004
665 Seven Pools, Hana 20.75469 -155.969
Corrected coordinates found by looking at Google Maps satellite imagery.
706 Harbor Lights 20.87778 -156.476
655 Ka`a Shoreline, Pa`ia 20.89897 -156.447
729 Wai`anapanapa 20.78859 -156.004
665 Seven Pools, Hana 20.66233 -156.041