Impact to Stream Water Quality from Sewage Exfiltration and Legacy On-Site Disposal Systems on the Island of O‘Ahu, Hawaii

steven spengler; marvin heskett

Outline

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Open Access

Research article

Impact to Stream Water Quality from Sewage Exfiltration and Legacy On-Site Disposal Systems on the Island of O‘Ahu, Hawaii

steven spengler¹^*

,

marvin heskett²

¹

Pacific Rim Water Resources, Hawaii 96734, USA

²

Element Environmental, LLC, USA

International Journal of Environmental Impacts

|

Volume 6, Issue 1, 2023

|

Pages 13-23

https://doi.org/10.18280/ijei.060103

Received: N/A,

Revised: N/A,

Accepted: N/A,

Available online: N/A

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Abstract:

The concentration of pharmaceutical compounds and nutrients present in perennial streams, springs and a lake on the island of O‘ahu, Hawai‘i were measured under drought conditions between 2020 and 2022. The combined island-wide daily release of wastewater to the environment on O‘ahu from the continued use of legacy On-Site Sewage Disposal Systems (OSDS) and from exfiltration from the 3,400-kilometer network of underground sewer lines has been estimated to be about 80 million liter per day (mld), or around 3.9% of the total island-wide groundwater flux to the ocean. The 36 streams and 11 springs sampled were located down-gradient of areas with varying densities of OSDS and sewage lines while the lake sampled (Lake Wilson) receives direct input from the wastewater treatment plant that serves Central O‘ahu. Average pharmaceutical and nutrient levels in streams and springs sampled in areas with high densities of OSDS and sewer lines were slightly higher, but not statistically different than concentration levels measured in streams and springs in areas with low densities of OSDS and low sewer line densities. The average sulfamethoxazole and carbamazepine levels measured in Lake Wilson, the only water body on O‘ahu where treated wastewater is discharged into fresh water, are three to four times higher than average levels measured in the island’s streams and springs. The presence of elevated concentrations of nitrate and silica in some streams and springs on O‘ahu predominately reflects the impact of the historical use of up-gradient lands for sugarcane cultivation rather than wastewater input. The trace levels of pharmaceuticals detected in O‘ahu streams and springs under baseflow conditions suggest that the actual combined input of wastewater to the environment from legacy OSDS and exfiltration from sewer lines is less than 20% the wastewater flux previously estimated.

Keywords: Baseflow, Cesspools, Hawaii, Oahu, OSDS, Pharmaceutical tracer, Septic tanks, Sewage exfiltration, Springs, Streams, Wastewater contamination

1. Introduction

2. Study Methodology

3. Sampling Results

4. Discussion

5. Conclusions

Data Availability

Appendix A contains the average pharmaceutical (caffeine, sulfamethoxazole, carbamazepine), nutrient (nitrate, ammonia, phosphate) and silica concentrations measured in the streams, springs, lake and septic tanks sampled during this study. The streams and springs are ordered based on the estimated density of cesspools and sewer lines present in the contributory watershed of the stream or spring sampled. The last column in the appendix describes whether the contributory watershed was historically used for large-scale agricultural purposes.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

References

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[2] American Society of Civil Engineers (ASCE). (2019). 2019 Hawaii Infrastructure Report Card. Retrieved from www.infrastructurereportcard.org/hawaii

[3] Amick, R.S., Burgess, E.H. (2000). Exfiltration in Sewer Systems. EPA/600/R-01/034, December 2000.

[4] Spengler, S.R., Heskett, M. (2022). Identification of sewage exfiltration in coastal areas through the monitoring of drugs and stimulant concentrations in urban storm drains. WIT Transactions on the Built Environment, 208: 67-79. [Crossref]

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[7] Oki, D.S., Brasher, A. (2003). Environmental setting and the effects of natural and humanrelated factors on water quality and aquatic biota, O‘ahu, Hawai`i. U.S. Geological Survey Water-Resources Investigations Report 03-4156.

[8] Cheng, C.L. (2016). Low-flow characteristics for streams on the Islands of Kaua‘i, O‘ahu, Moloka‘i, Maui, and Hawaii, State of Hawaii: U.S. Geological Survey Scientific Investigations Report 2016-5103, 36.

[9] Voss, C.I., Wood, W.W. (1993). Synthesis of geochemical, isotopic and groundwater modelling analysis to explain regional flow in a coastal aquifer of Southern O‘ahu, Hawai`i. In Mathematical models and their applications to isotope studies in groundwater hydrology. IAEA-TECDOC-777.

[10] Reyes, N.J.D.G., Geronimo, F.K.F., Yano, K.A.V., Guerra, H.B., Kim, L.H. (2021). Pharmaceutical and Personal Care Products in Different Matrices: Occurrence, Pathways, and Treatment Processes. Water, 13: 1159. [Crossref]

[11] Wilkinson, J.L., Boxall, A.B., Kolpin, D.W., Leung, K.M., Lai, R.W., Galbán-Malagón, C., Teta, C. (2022). Pharmaceutical pollution of the world’s rivers. Proceedings of the National Academy of Sciences, 119(8): e2113947119. [Crossref]

[12] Shelton, J.M., Kim, L., Fang, J., Ray, C., Yan, T. (2011). Assessing the severity of rainfall-derived infiltration and inflow and sewer deterioration based on the flux stability of sewage markers. Environmental Science & Technology, 45: 8683-8690. [Crossref]

[13] Hawaii Department of Health (HDOH). (2019). 2018 Groundwater Status Report. Appendix H: Assessing the Presence and Potential Impacts of Pharmaceutical and Personal Care Products (PPCPs) on Groundwater and Drinking Water.

[14] Visher, F.N., Mink, J.F. (1964). Ground-water resources in southern O‘ahu, Hawaii. U.S. Geological Survey Water-Supply Paper 1778, 133.

[15] Deenik, J.L. (1997). Liming effects on nitrate adsorption in soils with variable charge clays and implications for ground water contamination: M.S. thesis, University of Hawaii at Manoa, 140.

[16] Davis, S.N. (1969). Silica in Streams and Ground Water in Hawaii. Water Resources Research Center Technical Report No. 20, January 1969.

Appendix

Average Pharmaceutical (Caffeine, Sulfamethoxazole and Carbamazepine) and Nutrient Concentrations in Septic Tanks and Lake Wilson and in Streams and Springs Located in Areas of Varying Densities of Cesspools and Sewer Lines.

Appendix A
Location	# of Immuno-Assay Analyses		Caffeine (ppt)	Sulfa. (ppt)	Carb. (ppt)	Nitrate (NO3-N) (ppm)	Ammonia (NH4) (ppm)	Phosphate (ppm)	Silica (ppm)	Large-Scale Ag?
Wastewater Source
Septic Tanks	26		23,614	1,630	745	13.1	85.5	44.9	NM	NA
High Density Cesspool / High Density Sewer Contributory Area
Waimanalo Seep	42		762	0.0	7.1	0.7	0.22	0.41	4	NO
Makiki Stream	18		621	18.0	1.4	0.4	0.08	0.75	22	NO
Inoaole Stream	8		515	0.0	1.8	0.0	0.42	1.57	–	YES
Loi Kalo Spring	16		345	0.0	0.0	0.0	0.08	0.34	39	NO
Waolani Stream	31		256	0.0	5.3	0.6	0.11	0.54	23	NO
Kalauao Stream	9		238	0.0	0.2	0.3	0.03	0.37	48	NO
Heeia Stream	4		236	0.0	–	0.4	0.03	0.12	29	YES
Manoa/Palolo Stream	26		232	4.7	0.3	0.2	0.08	0.34	20	NO
Kahawai Stream	26		200	0.0	0.1	2.6	0.15	0.30	36	YES
Ie Ie Park Spring	18		198	0.0	0.0	0.8	0.06	0.46	48	NO
Kalihi Stream	21		196	0.0	2.2	0.5	0.05	0.40	17	NO
Kunawai Spring	8		157	0.0	0.3	0.0	0.07	0.65	30	NO
Ahuimanu Stream	10		130	0.0	0.0	0.1	0.03	0.17	25	NO
Kahaluu Stream	11		63	0.0	0.0	0.2	0.03	0.22	27	NO
Nuuanu Stream	5		0	0.0	0.0	0.1	0.08	0.30	15	NO
Pauoa Stream	7		–	–	0.0	0.0	0.05	0.70	20	NO
Waialae Nui Stream	4		–	–	0.0	0.2	0.62	0.19	–	NO
Kaupuni Stream	0		–	–	–	0.0	0.03	0.31	–	YES
High Density Cesspool / Low Density Sewer Contributory Area
Waihee Stream	4		272	0.0	–	0.0	0.02	0.24	27	YES
Anahulu Stream	12		168	0.0	0.0	1.2	0.06	0.43	37	YES
Paukauila Stream	9		167	0.0	0.0	0.5	0.20	0.67	45	YES
Waimanalo Stream	17		141	0.0	0.2	0.2	0.06	0.23	31	YES
Loko Ea Fishpond	12		70	0.0	0.0	2.9	0.04	0.30	48	YES
Kiikii Stream	9		0	0.0	0.0	1.5	0.25	0.66	35	YES
Haaula Seep	4		–	–	0.0	–	–	–	–	NO
Kaunala Seep	12		–	–	0.3	0.0	0.49	0.29	2	NO
Anahulu River Spring	0		–	–	–	2.5	0.03	0.92	69	YES
Low Density Cesspool / High Density Sewer Contributory Area
Ulupo Heiau Spring	17		670	0.0	2.5	1.2	0.03	1.96	33	NO
Pukele Stream	4		304	0.0	0.0	0.8	0.16	0.40	19	YES
Waimano Stream	30		295	3.0	2.2	0.4	0.08	0.45	43	NO
Waipahu Spring	23		235	0.0	0.2	0.7	0.08	0.78	47	YES
Kapakahi Stream	26		215	0.0	0.3	0.3	0.11	0.82	52	YES
Kaneohe Stream	8		173	0.0	0.3	0.8	0.03	0.22	22	NO
Waikele Stream	8		172	0.0	0.0	1.0	0.02	0.66	48	YES
Kalauoa Spring	9		128	0.0	0.0	0.0	0.01	0.78	43	NO
Keaahala Stream	14		128	0.0	0.3	0.1	0.02	0.25	28	NO
Kawa Stream	23		88	2.3	0.5	0.7	0.04	0.53	17	NO
HECO Spring		5	86	0.0	0.0	0.0	0.00	0.70	–	NO
Moanalua Stream		0				0.1	0.11	0.51	22	NO
Maunawili Stream		0	–	–	–	0.4	0.05	0.29	23	NO
Low Density Cesspool / Low Density Sewer Contributory Area
Waiawa Stream		11	228	0.0	0.0	0.0	0.16	0.21	21	YES
Kapaa Stream		19	168	2.1	0.0	0.1	0.21	0.51	27	NO
Kahana Stream		18	0		0.0	0.1	0.03	0.02	22	NO
Kahuku Stream		2	–	–	0.0	0.0	0.03	0.86	48	YES
Honouliuli Stream		0	–	–	–	0.7	0.07	0.30	25	YES
Kahana Iki Stream		0	–	–	–	0.0	0.05	0.21	31	NO
Samples from Lake Wilson and Outlet Streams (Kaukonahua) and Ditch (Wahiawa)
Kaukonahua Stream		16	730	9.7	1.5	0.0	0.13	2.63	7	NO
Wahiawa Ditch		22	326	2.8	4.9	0.0	0.09	0.22	8	NO
Lake Wilson		104	214	1.9	10.9	0.0	0.08	0.19	8	NO
COMbINED		142	251	2.4	5.7	0.0	0.08	0.30	8	NO

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Spengler, S. & Heskett, M. (2023). Impact to Stream Water Quality from Sewage Exfiltration and Legacy On-Site Disposal Systems on the Island of O‘Ahu, Hawaii. Int. J. Environ. Impacts., 6(1), 13-23. https://doi.org/10.18280/ijei.060103

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