Sewage Injection Wells Pollute Coastal Waters

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Partially treated sewage gets dumped in a deep hole.

Large sewage injection wells are permitted, and Gang Cesspools are not

R.H. Bennett, Ph.D.

Applied Life Sciences LLC and Kona Waterkeepers

Most people will likely react to this title with another question. What is an injection well? In Hawaii, an injection well is a hole deeper than it is wide and allows the flow of liquids into the ground. In the state, they are used to dispose of partially treated sewage or stormwater. It may or may not be lined or pipe fitted.

A gang cesspool is defined as follows. “Residential multiple-dwelling, community, or regional systems (e.g., townhouse complexes or apartment buildings) that dispose of sanitary waste or Non-residential cesspools that have the capacity to serve 20 or more persons per day per the EPA (5)”.

Sewer injection wells are fundamentally not different from gang cesspools. So why is one permitted and the other banned? Both systems have the potential to contaminate drinking water. Injection wells are regulated under federal statute, implemented by the state (4).

In Hawaii, all injection wells are used solely to dispose of rainwater, stormwater runoff, and sewage. That is right, partially treated wastewater can be put down a well and allowed to percolate to the groundwater below. In the mainland, injection wells can go very deep and below drinking water aquifers. On an island, the brackish groundwater circulates to and from the sea by tidal action. Some brackish groundwater flows in Kona are millions of gallons per day. The cold spots we swim into are due to this flow.

 Our island is not at all like Kansas. Brackish groundwater penetrates the inland. Inland percolated rainwater floats on the saline groundwater. This floating water is our drinking water.

Underground injection wells are limited to the near-coastal zone as depicted by a UIC (Underground Injection Control) line around each island. The line sites injection wells close to the coast. Drinking water is protected by locating these wells nearshore and away from the upslope drinking water wells. No one would argue with that logic. However, below the line, near the ocean side of the UIC line, wastewater, stormwater, and sewage can be injected. Yet, where does this hazardous liquid go? It joins the brackish groundwater flowing toward the sea. It has nowhere else it can go. The fate of these pollutants is entirely unregulated.

Per the State of Hawai‘i, the marine waters off the Kona Coast are Class AA Pristine and to be kept in their “wilderness” state (HAR 11-54). How can the pristine state be possible when the polluted wastewater is flowing into the sea in seeps and lava tubes?

It is unlawful to run a wastewater pipeline into the sea without demonstrating via the permit process that the wastewater will not degrade the receiving waters. On Hawaii Island, there are at least two such pipeline permitted discharges operated by Hawaii County. In great contrast, Honolulu still pipes untreated sewage directly offshore. This still occurs in spite of a 2010 Consent Decree, where the city agreed to abate the polluting discharges.

In an injection well, the pipeline or well casing does not enter the sea. As Supreme Court Justice Kagan suggested during oral testimony on the Maui Case, if the underground pipeline stopped five feet from the sea, are we to presume that would be a permissible discharge? In the Maui injection well case, the Ninth Federal Circuit court said no. They said underground geologic conduits are fundamentally no different than a pipeline draining into the sea. Therefore, a discharge permit is required.

According to the Department of Health, Clean Water Branch, Underground Injection Control Program, or UIC, Hawaii island has 613 sewage injection wells. However, a limited review suggests many of these wells are closed where sewer service is available. Sewage in the context of the UIC program is all wastewater from domestic and commercial plumbing. Sewage treatment is to the Secondary Level, to include the removal of suspended and dissolved solids. There is no requirement for disinfection or nutrient removal.

An individual injection well is rather primitive as most are gravity fed. An example is shown below.

Professor Frank L Peterson of the University of Hawaii was the first to raise concerns about injection well performance and potential contamination of the nearshore waters in 1985.

"The extent of shallow coastal-water contamination is more problematic. Wastewater injected into coastal aquifers only a few tens or hundreds of meters from the shore must discharge, virtually undiluted, directly into the coastal waters” (3).

He went on to suggest that the functional life span of an injection well may only be a matter of a few years due to clogging and fouling. The performance of injection wells today is mostly unknown to the state for the lack of the required inspections.

On Hawaii Island, major injection wells operate as part of the Honoka'a wastewater treatment plant and found at some of the resorts on the Kona Coast. One such well is located very near the shoreline, as required, and can dispose of 400000 gallons of secondary sewage per day. The nutrients in this wastewater are detrimental to the nearshore ecosystem and especially the corals (2,6). In contrast, many Kona resorts the wastewater is reused to irrigate the golf course and grounds. Turf does a reasonable job of removing the fertilizing nutrients. This reuse conserves freshwater in the upslope and nearby aquifers.

 

The addition of wastewater nutrients to the sea is well documented to be deadly to coral, especially during warm water stress.

https://hilo.hawaii.edu/faculty/wiegner/documents/faculty/wiegner/publications/Abayaetal.2018b.pdf

Recently the state instituted a law to limit the use of sewage injection wells. Act 131 (2018) provides that the Health Department Director shall not issue permits for the construction of sewage wastewater injection wells unless alternative wastewater disposal options are not available. In most cases, some options require a higher level of sewage treatment that removes nutrients and pathogens(1). Perhaps this new law will provide some incentive to examine the benefits of water reuse as we move into an era of radical climate change.

The reason that Gang Cesspools are banned and injection wells are not is that the siting of injection wells is only permitted downslope far away from drinking water wells. The logic obeys the simple physics of gravity on water.

Under the UIC program, there is no accounting for the impact of the wastewater on the environment because a human-made conduit does not convey the wastewater directly into the waters of the United States. That makes about as much practical environmental policy sense as screen doors on submarines. All nearshore groundwater polluted or not, eventually flows into the sea.

Most of our nearshore waters are Federally-Listed as Impaired under the rules of the 1972 Clean Water Act. The law requires the state to regulate these impaired waters and prevent further impairment. The EPA and the state have done absolutely nothing to apply the law on this island. The net effect is to provide local business and government the cheapest wastewater disposal method possible.

 We can only hope the Justices will use the same common sense applied by the Ninth Circuit Court in its ruling on the Maui wastewater injection wells. However, that optimism is wistful given the recent appointments to the court.

 The Constitution of the State of Hawaii contains the Public Trust Doctrine. This doctrine requires the state to act in the public trust when it manages the state’s natural resources.  When the state allows the dumping of sewage wastewaters into the ground near the sea, it violates that trust. It is we the people that will have to bear the cost of such a polluters subsidy.

References

1. Hawaii Department of Health GUIDELINES FOR THE TREATMENT AND USE OF RECYCLED WATER (2013) https://health.hawaii.gov/wastewater/files/2016/03/03_V1_RWFacilities.pdf

2. Lapointe, Brian E., Peter J. Barile, Mark M. Littler, and Diane S. Littler. "Macroalgal blooms on southeast Florida coral reefs: II. Cross-shelf discrimination of nitrogen sources indicates widespread assimilation of sewage nitrogen." Harmful Algae 4, no. 6 (2005): 1106-1122.

3. Peterson, FRANK L., and June Ann Oberdorfer. "Uses and abuses of wastewater injection wells in Hawaii." Pacific Science 39, no. 2 (1985): 230.

4. US EPA Safe Drinking Water Act, Underground Injection Control. https://www.epa.gov/uic/underground-injection-control-regulations-and-safe-drinking-water-act-provisions

5. US EPA What is a large capacity cesspool https://www.epa.gov/uic/cesspools-hawaii#whatis

6. USGS 2018 Polluted Groundwater Threatens Coral Reefs https://www.usgs.gov/center-news/polluted-groundwater-threatens-hawaiian-coral-reefs?qt-news_science_products=4#qt-news_science_products

Splenda may solve our problem.

Your Coffee Sweetener May Help Make Recreation Water Safer.

R.H. Bennett Ph.D.

Applied Life Sciences LLC

Honaunau, Hawai‘i

The coffee and tea drinkers that like it sweet but don't use sugar are giving us a handle on a greased watermelon that has slipped through our hands for decades.   The artificial sweetener Splenda may turn to provide a marker of wastewater and sewage that “flows” into the environment.  Sweden, Arizona, Maine, and Florida scientists confirm that Splenda, Sucralose is a reliable wastewater indicator.  Our work, slated for this fall, will likely show the assay reliable in Hawaii too.

In this era of great scientific achievement, we can identify a single gene on one strand of human DNA.  Advanced analytical methods can detect toxicants as low a few parts per trillion in water or food. ( one part per trillion is one second in 31.7 thousand years)  Molecular proteomics can detect tumor proteins long before an MRI will ever visualize the tumor.

 Given these exceptional abilities, it would be reasonable to expect we can detect traces of sewage in the waters of Hawai‘i; paradoxically we cannot. It has been that way for almost four decades with no advances. Confirmation of a sewage spill or leak still requires a visual assessment.  Alternatively, we assume elevated levels of Indicator Bacteria reveal sewage contamination.  Unfortunately, all the bacterial indicators used over the last  100 years are replete with false positives and negatives for the assessment of pathogen presence in water (Noble 2003).

 The currently used official indicator test for the bacterial genus Enterococci is written in stone in both Federal and State law.  Refer to Colford (2012) for a detailed review of the shortcomings of the Enterococci test to predict illness risk.  In short, the test has one chance in two for detecting sewage pathogens in surface waters without known sewage outfalls like the one at Sand Island Oahu.  Would we feel safe driving our cars if the break failure indicator light only worked half the time?

Other Sewage Indicators

Water quality researchers have taken several approaches to find a valid sewage contamination indicator.  Fairly recently, certain pharmaceuticals, caffeine, and nicotine metabolites showed some promise. However, most do not persist across the vast array of sewage processing and disposal technologies.  Sewage treatment operates processes to break down the components of sewage and the indicators are typically not resistant to degradation.

A reliable indicator must persist through most treatment processes and endure over time.  They must resist photodegradation from sunlight, and they must resist microbial decomposition.  A valid indicator must not cross-react with other chemicals in the sewage milieu and create false positives.

Advanced microbial detection of human fecal pathogens using DNA/RNA technology shows much promise and precision. Both  PCR and Nextgen sequencing offers excellent precision and accuracy. However, the technique requires a commercial laboratory equipment expertise that is not currently available. The biggest problem is the long turnaround times needed to produce actionable data for the regulatory agencies.

Sucralose as an ideal Indicator: The Evidence

The artificial sweetener Sucralose (Splenda) is a very widely used sugar substitute. It is an ingredient in over 4000 consumer products worldwide.  It is a simple carbohydrate; however, it has three chlorine molecules attached.  As a chlorinated carbohydrate, it is not digestible and not metabolized by bacteria in the gut or the environment.

In the figure below, its chemical structure is similar to table sugar, sucrose, yet note the three chlorine molecules (green).  As such it is a member of a class of chemicals called chlorinated organics.  This class of compounds tends to be very stable and persistent in the environment.

In humans ingesting Sucralose, it is poorly absorbed, and the mean residence time is 19 hours.  Half-life is 13 hours.  Most is excreted in the feces, 78% and 15% in the urine. It is mainly excreted unchanged. Only 2.6% is excreted as a glucuronide conjugate (Roberts 2000).

Sucralose survives a wide variety of wastewater treatment processes with minimal and insignificant degradation from oxidation or UV irradiation.  It is not degraded by anaerobic or aerobic microbial wastewater treatment. Sucralose survives waste treatment essentially unchanged in wastewater effluent at concentrations ranging from 1800 to 3800 nanograms per L. (Torres 2011).

In waters receiving wastewater in any form, Sucralose exists in fresh and marine waters.  Extensive studies in Sweden Sucralose show 400 to 900 ng/L downstream of a wastewater treatment plant Upstream it was less than 4ng/L (the minimum detection limit or MCL) (Brorström-Lundén (2008).  Sucralose testing in the open ocean and the marine waterways of Florida demonstrated its wide distribution. In the ocean waters of the Florida Keys, Sucralose was routinely detected at concentrations ranging from 147 ng to 393 ng per liter (Mead 2009).

In a recent Florida study, Sucralose levels above the MCL was detected in 78% of the samples, from slightly brackish to marine waters, ranging from 8 to 148 ng/L. A treated wastewater ocean outfall tested at 8414 ng/L in the Miami area (Batchu 2013).  These data confirm the assay method is sound for very diluted Sucralose in environmental waters.

Since estuaries in the United States are commonly used for both direct and indirect discharge of treated and untreated wastewater, questions about the suitability of using Sucralose as a wastewater proxy in estuaries may arise.  The question is answered by a recent study in the Narragansett Bay Estuary in Maine.  Researchers found that Sucralose was readily detected in estuarian waters. Sucralose concentrations had an r² = 0.88 correlation with salinity (Cantrell 2019).

Among the numerous chemical markers of sewage, including pharmaceuticals and other artificial sweeteners, Sucralose has the advantage of wider distribution and environmental persistence.  It is the preferred chemical indicator for sewage, wastewater, septage and cesspool leachate. In time, Sucralose may become the preferred indicator for the presence of fecal bacteria and virus. One study in a tropical urban environment demonstrated that Sucralose concentrations had the strongest correlation with the common sewage indicator bacteria counts over other chemical indicators.  The correlation values ranged from 0.40 to 0.47 (Ekklesia, 2015).  The low R values are attributed to the lack of precision in the bacteria test methods and not the chemical assay for Sucralose.

The Sucralose Assay

Sucralose is available in pure analytical grade making most any assay for it highly confirmable. The preferred analytical method is one that is precise and accurate while being rapid and lower in cost.  The technique developed by Batchu et al. (2015) includes online solid-phase extraction coupled with orbitrap high-resolution mass spectrometer.  This

method is rapid and lesser cost compared to HPLC mass spectrometry. 

The HRMS method is capable of discriminating between sucralose molecules that differ only by the deletion of one chlorine molecule.  Thus, its precision and accuracy allow detection of Sucralose down to 1.4 nanograms per liter (minimum detection limit).  A nanogram is one billionth of a gram. A billionth is three seconds in one hundred years.

This means even very little Sucralose diluted in household wastewater, then further diluted, in sewage and then even further diluted in nearshore ocean water is detectable. Mawhinney (2011) describes sucraloseʻs presence in drinking water systems, including the point of consumption.  These researchers used another method of detection and obtained excellent precision and accuracy with this second method.  It further attests to the validity of Sucralose as a wastewater indicator

But some may ask how precise the assay is?  As it turns out, Orbitrap High-Resolution Spectrometry is very precise (Hornshaw 2015).  As can be seen in the chemical structure diagram, Sucralose has three chlorine molecules.   What will this assay detect if we add some faux sucralose, one that has only two chlorine molecules?   The assay can distinguish the two chlorine faux sucralose form the three chlorine real thing.  This means the likelihood of a similar molecule becoming a false positive is highly unlikely.

The concepts of precision and accuracy may be a tad foreign.  The target analogy is a simple way to understand the terms.  The assay for Sucralose fits the pattern in the lower right.  The assay detects the amount correctly and does so consistently.  It is accurate an precise.  Reliable data derives from the type of assay technology and proper calibration with each use.

Given that two Sucralose assays demonstrate accurate and precise measurements and given that Sucralose is reliably detected in waters and climates from Sweden to Arizona, the assay is validated. 

What is needed now to enable Sucralose for the official EPA wastewater/sewage indicator in a human epidemiology study.  Such a prospective study could be conducted at a major urban beach to determine recreation water exposure.  Exposures such as wading vs. swimming vs. surfing associated with post recreation illnesses, including GI, skin, eye, and upper respiratory diseases.   The theory being Sucralose is present when wastewater is present.   Sucralose is stable, not inactivated by sunlight UV.  The concentration of Sucralose in recreation water may be directly proportional to the concentration of human virus and bacteria capable of causing disease.   This type of research is costly, yet an excellent investment in finding more effective means to monitor recreation water microbiological safety.  In Hawai‘i that is rather important, to say the least.

Sweet coffee anyone?

References

Batchu, Sudha Rani, Natalia Quinete, Venkata R. Panditi, and Piero R. Gardinali. "Online solid phase extraction liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) method for the determination of sucralose in reclaimed and drinking waters and its photo degradation in natural waters from South Florida." Chemistry Central Journal7, no. 1 (2013): 141.

Brorström-Lundén, Eva, Anders Svenson, Tomas Viktor, Andreas Woldegiorgis, Mikael Remberger, Lennart Kaj, Christian Dye, Arve Bjerke, and Martin Schlabach. "Measurements of Sucralose in the Swedish Screening Program 2007: PART I; Sucralose in surface waters and STP samples." (2008).

Cantwell, Mark G., David R. Katz, Julia Sullivan, and Anne Kuhn. "Evaluation of the artificial sweetener sucralose as a sanitary wastewater tracer in Narragansett Bay, Rhode Island, USA." Marine Pollution Bulletin 146 (2019): 711-717.

Colford Jr, John M., Kenneth C. Schiff, John F. Griffith, Vince Yau, Benjamin F. Arnold, Catherine C. Wright, Joshua S. Gruber et al. "Using rapid indicators for Enterococcus to assess the risk of illness after exposure to urban runoff contaminated marine water." Water research 46, no. 7 (2012): 2176-2186.

Ekklesia, E., Shanahan, P., Chua, L., & Eikaas, H. (2015). Associations of chemical tracers and faecal indicator bacteria in a tropical urban catchment. Water research, 75, 270-281.

Hornshaw, M. (2015) Why is the Orbitrap Mass Analyzer so Amazing? http://analyteguru.com/why-is-the-orbitrap-mass-analyzer-amazing/

Loos, Robert, Bernd Manfred Gawlik, Kristin Boettcher, Giovanni Locoro, Serafino Contini, and Giovanni Bidoglio. "Sucralose screening in European surface waters using a solid-phase extraction-liquid chromatography–triple quadrupole mass spectrometry method." Journal of Chromatography A 1216, no. 7 (2009): 1126-1131.

Mawhinney, Douglas B., Robert B. Young, Brett J. Vanderford, Thomas Borch, and Shane A. Snyder. "Artificial sweetener sucralose in US drinking water systems." Environmental science & technology 45, no. 20 (2011): 8716-8722.

Mead, Ralph N., Jeremy B. Morgan, G. Brooks Avery Jr, Robert J. Kieber, Aleksandra M. Kirk, Stephan A. Skrabal, and Joan D. Willey. "Occurrence of the artificial sweetener sucralose in coastal and marine waters of the United States." Marine Chemistry 116, no. 1-4 (2009): 13-17.

Noble, Rachel T., Douglas F. Moore, Molly K. Leecaster, Charles D. McGee, and Stephen B. Weisberg. "Comparison of total coliform, fecal coliform, and enterococcus bacterial indicator response for ocean recreational water quality testing." Water research 37, no. 7 (2003): 1637-1643.

Oppenheimer, Joan, Andrew Eaton, Mohammad Badruzzaman, Ali W. Haghani, and Joseph G. Jacangelo. "Occurrence and suitability of sucralose as an indicator compound of wastewater loading to surface waters in urbanized regions." Water research 45, no. 13 (2011): 4019-4027.

Roberts, A., A. G. Renwick, J. Sims, and D. J. Snodin. "Sucralose metabolism and pharmacokinetics in man." Food and chemical toxicology 38 (2000): 31-41.

Torres, César I., Smitha Ramakrishna, Chao-An Chiu, Katherine G. Nelson, Paul Westerhoff, and Rosa Krajmalnik-Brown. "Fate of sucralose during wastewater treatment." Environmental Engineering Science 28, no. 5 (2011): 325-331.