The long wait has ended. Researchers have now verified what many people had suspected for years: wastewater from the Lahaina sewage treatment plant, on Maui\u2019s Ka`anapali Coast, is reaching coastal waters.<\/p>\n
Starting in late July, scientists with the University of Hawai`i injected copious amounts of fluorescein dye \u2013 340 pounds of it \u2013 into two of the wells used by Maui County to dispose of treated wastewater at the Lahaina plant.<\/p>\n
That was followed on August 11 by the injection of 180 pounds of rhodamine dye into a third injection well, which lies further mauka.<\/p>\n
By putting dye into the wastewater, the researchers were seeing if they could confirm suspicions that it was reaching \u2013 and possibly contaminating \u2013 coastal waters. Those suspicions, going back more than two decades, were heightened in 2010. That year, two serious scientific studies were published that reported finding in coastal seeps downstream of the injection wells the type of chemical and biological profiles typically associated with wastewater. (For a full account of these studies, see the May 2010 issue of Environment Hawai`i<\/i>.)<\/p>\n
For Maui County, the reports could not have come at a worse time. The county was seeking to renew permits for the Lahaina injection wells, and the U.S. Environmental Protection Agency was considering whether to require the plant to obtain a National Pollutant Discharge Elimination System (NPDES) permit for it as well, given the apparent connections between the injection wells and the ocean.<\/p>\n
The county protested that the studies were speculative and that no definitive link was established between the injection wells and the coastal seeps. The EPA backed off, agreeing to allow the dye tests to go forward and to require the county, in the meantime, to ramp up chlorination of the injected wastewater.<\/p>\n
A Long Vigil<\/i><\/b><\/p>\n
For the first month following the dye injection, sampling along the coastal seeps was done twice a day, according to people involved with the tests. After a month, that slipped to daily or every other day.<\/p>\n
On October 6, Gary Gill, deputy director of the Department of Health, said at a University of Hawai`i seminar that although \u201cgobs and gobs\u201d of dye had been injected, \u201cnothing\u2019s come up in the coastal area.\u201d<\/p>\n
But the sampling of submarine springs continued, and, before the month was out, samples at some of the locations began to show elevated levels of fluorescein.<\/p>\n
\u201cThat concentration \u2013 above the baseline levels, which told the researcher something significant is going on \u2013 has continued to rise and is now very clearly present,\u201d said David Albright, manager of the groundwater and underground injection control program for the EPA\u2019s Region IX, in San Francisco. \u201c<\/p>\n
The rhodamine dye had not yet turned up by mid-January, but Albright explained that the well into which the rhodamine dye had been placed was about a hundred yards further inland than the two wells receiving the fluorescein. \u201cWe expected it would take longer [for the rhodamine to show up], since it had to travel further,\u201d he said in a telephone interview with Environment Hawai`i.<\/p>\n
Do the long delays between the injection of the dyes and their detection at the coast give researchers an idea of the travel time required for wastewater to meet the coast, Albright was asked.<\/p>\n
At this point, he replied, \u201ccertainly it\u2019s an indicator of travel time for something, but I wouldn\u2019t say that since the dye took this long, the injection fluid does as well.\u201d<\/p>\n
Permitting<\/i><\/b><\/p>\n
Albright would not say whether the EPA would now be requiring the county to obtain an NPDES permit for the injection wells. \u201cThe detection of fluorescein confirms that there\u2019s a connection [between wells and ocean],\u201d he said.<\/p>\n
\u201cBut is that a trigger for an NPDES permit? I\u2019d say it\u2019s too early to say. We need to get a sense of travel time, a sense of what is being discharged. That will be important, and that monitoring is only now starting to occur.\u201d<\/p>\n
The Department of Health, he continued, is starting to monitor seeps for bacterial indicators, nutrients, and a number of other standard wastewater constituents. \u201cThus far, the data that have been collected \u2013 very preliminary, at least for pathogens \u2013 are negative, showing none of the bacterial indicators they\u2019ve sampled for.\u201d<\/p>\n
Albright acknowledged, however, that the failure to detect bacterial indicators of wastewater might be linked to the increased chlorination at the plant, which began in early October. \u201cPursuant to the agreement worked out between the EPA and the county,\u201d he said, \u201cthey\u2019ve increased the level of chlorination to what would be R-2 level wastewater.\u201d<\/p>\n
Warmer Water<\/i><\/b><\/p>\n
Another area of research that has shown results, Albright said, was an infrared thermal survey of the West Maui coast. That, he said, \u201cinvolved flying over the area, using sophisticated instruments to measure a thin layer of surface water for temperature variations.\u201d<\/p>\n
The instruments were highly sensitive and accurate, and could detect very small variations in the surface water temperature, he continued.<\/p>\n
\u201cWhat they saw with the data they collected was a sizable plume of warmer water around the seeps,\u201d he said. The finding was confirmed in direct measurements of the temperature of water coming out of the seeps, where the temperatures were on the order of one to two degrees Centigrade higher than the surrounding ambient ocean water.<\/p>\n
Groundwater is usually cooler than ocean water, so the fact that the seeps discharge warmer water also tends to confirm the presence of wastewater.<\/p>\n
The researchers also looked at isotopes of nitrogen in the samples taken from the seeps. The results, said Albright, \u201cwere consistent with the findings of Chip Hunt and Megan Dailer,\u201d the principal authors of the two earlier studies. \u201cWaters that migrate to the coast from the [wastewater] facility and upgradient wells are undergoing significant microbial nitrate reduction.\u201d<\/p>\n
\u201cAmbient ocean water has next to no nitrates,\u201d he said.<\/p>\n
Patricia Tummons<\/b><\/p>\n
Volume 22, Number 8 — February 2012<\/p>\n","protected":false},"excerpt":{"rendered":"
The long wait has ended. Researchers have now verified what many people had suspected for years: wastewater from the Lahaina sewage treatment plant, on Maui’s Ka`anapali Coast, is reaching coastal waters. Starting in late July, scientists with the University of … Continued<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-471","post","type-post","status-publish","format-standard","hentry","category-february-2012"],"_links":{"self":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/posts\/471","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=471"}],"version-history":[{"count":0,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/posts\/471\/revisions"}],"wp:attachment":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=471"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=471"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=471"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}