{"id":561752,"date":"2025-02-26T18:39:13","date_gmt":"2025-02-26T18:39:13","guid":{"rendered":"https:\/\/uat.esri.com\/en-us\/industries\/blog\/?post_type=blog&#038;p=561752"},"modified":"2025-04-07T22:19:21","modified_gmt":"2025-04-07T22:19:21","slug":"from-data-to-decision-making-how-gis-powers-hawaiis-cesspool-replacement-efforts","status":"publish","type":"blog","link":"https:\/\/www.esri.com\/en-us\/industries\/blog\/articles\/from-data-to-decision-making-how-gis-powers-hawaiis-cesspool-replacement-efforts","title":{"rendered":"From Data to Decision-Making: How GIS Powers Hawaii\u2019s Cesspool Replacement Efforts"},"content":{"rendered":"<p class=\"undefined block-editor-paragraph\"><em>By Chris Shuler, Mike Mezzacapo, and Melanie Lander<\/em><\/p>\n\n<h2 class=\"wp-block-heading\" id=\"h-a-problem-in-paradise\"><strong>A Problem in Paradise<\/strong><\/h2>\n\n<p class=\"undefined block-editor-paragraph\">The Hawaiian Archipelago, set in tropical blue waters and lined with picture-perfect, white-sand beaches, attracts nearly 10 million visitors each year. But beneath the surface, an estimated 83,000 cesspools leak about 53 million gallons of untreated wastewater into the ocean each day. Cesspools, the most rudimentary of on-site wastewater systems, are common across the islands. <\/p>\n\n<p class=\"undefined block-editor-paragraph\">A cesspool is simply an underground pit or porous tank that is used to collect wastewater. The cesspool is literally the oldest known wastewater disposal technology, dating back to ancient Babylonia in 4000 BC.\u00a0 In the U.S. they were commonly used\u00a0in areas without access to a centralized\u00a0sewage system. Now, due to environmental regulations, more advanced systems like septic tanks are generally\u00a0required.\u00a0Cesspools are typically made from concrete, brick or stone, and have porous walls or an open bottom to allow the water to seep into the surrounding soil.<em>\u00a0<\/em>Wastewater from cesspools not only contaminates coastal waters with harmful bacteria and coral-choking nutrients, but also impacts drinking water supplies and inland aquatic environments.<\/p>\n\n<p class=\"undefined block-editor-paragraph\">In 2017, Hawaii\u2019s state legislature took decisive action to address the widespread contamination threat posed by cesspools across the islands. Act 125 mandated the replacement of these substandard wastewater systems by 2050 and signaled the start of an ambitious journey to protect Hawaii\u2019s drinking water, coastal ecosystems, and public health.&nbsp;<\/p>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"624\" height=\"261\" src=\"https:\/\/uat.esri.com\/en-us\/industries\/blog\/wp-content\/uploads\/2025\/02\/Illustration.png\" alt=\"\" class=\"wp-image-561782\" srcset=\"https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Illustration.png 624w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Illustration-300x125.png 300w\" sizes=\"auto, (max-width: 624px) 100vw, 624px\" \/><figcaption class=\"wp-element-caption\"><em>How cesspools leak wastewater into groundwater and coastal environments.<\/em><\/figcaption><\/figure>\n<\/div>\n\n<p class=\"undefined block-editor-paragraph\">However, with Hawaii\u2019s diverse landscapes\u2014from densely populated neighborhoods to rural coastal zones\u2014implementing this mandate is a formidable undertaking. Breaking the process down into systemic and manageable steps is essential. In this case, the first crucial step was to prioritize which cesspools were most important to replace based on their potential impacts. Previous prioritization methods depended on limited and expensive water quality studies of individual areas. However, a legislative task force created by Hawaii Act 132, the Cesspool Conversion Working Group (CCWG), recognized the need for a more sophisticated, data-driven tool to ensure fair and effective prioritization across the state.<\/p>\n\n<p class=\"undefined block-editor-paragraph\">To meet this challenge, a partnership between the University of Hawaii Water Resources Research Center, the Hawaii Sea Grant College Program, and the Hawaii State Department of Health was established to create the Hawaii Cesspool Prioritization Tool (HCPT). The tool was developed with advanced GIS methodologies, leveraging the ArcPy modules along with diverse datasets to perform transparent and reproducible spatial analysis of cesspool-derived environmental and public health impacts. By integrating data on groundwater flow, proximity to drinking water sources, ecological sensitivity, and sea level rise projections, the GIS framework enables a targeted, risk-based cesspool replacement timeline across Hawaii.<\/p>\n\n<h2 class=\"wp-block-heading\" id=\"h-transforming-data-into-actionable-insights-the-development-of-the-hcpt\"><strong>Transforming Data into Actionable Insights: The Development of the HCPT<\/strong><\/h2>\n\n<p class=\"undefined block-editor-paragraph\">Creating a targeted cesspool replacement plan for Hawaii presented an immediate challenge. The sheer number and geographic spread of cesspools across Hawaii\u2019s diverse landscapes required a tool that could simplify complex, site-specific data into actionable insights for managers, community organizations, and the public. For this effort, accurate data was fundamental, yet the state\u2019s understanding of cesspool locations and their impacts was limited. Existing records lacked the detail needed to guide policy effectively, making it essential to leverage knowledgeable experts and robust datasets to create a more accurate cesspool inventory and a comprehensive set of risk factors.<\/p>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"624\" height=\"435\" src=\"https:\/\/uat.esri.com\/en-us\/industries\/blog\/wp-content\/uploads\/2025\/02\/Cesspool.png\" alt=\"\" class=\"wp-image-561822\" srcset=\"https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Cesspool.png 624w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Cesspool-300x209.png 300w\" sizes=\"auto, (max-width: 624px) 100vw, 624px\" \/><figcaption class=\"wp-element-caption\"><em>&nbsp;A cesspool in Ka\u2018a\u2018awa, O\u2018ahu, exposed by shoreline erosion.<\/em><\/figcaption><\/figure>\n<\/div>\n\n<p class=\"undefined block-editor-paragraph\">To individually assess 83,000 cesspools, powerful GIS capabilities and efficient database management were essential. The HCPT was designed to address this massive volume of data and complexity by integrating diverse environmental risk factors\u2014ranging from groundwater proximity to coastal exposure\u2014in one platform. ArcPy, a Python library within ArcGIS, became instrumental in automating the analytical workflows needed to assess each cesspool\u2019s impact. ArcPy\u2019s robust scripting capabilities enabled the project team to efficiently manage large datasets and define complex relationships across layers. This approach allowed the HCPT to handle intricate dependencies among datasets and assign meaningful risk scores to each cesspool.<\/p>\n\n<p class=\"undefined block-editor-paragraph\">Whether assessing proximity to drinking water sources, mapping groundwater flow, or predicting coastal flooding from sea level rise, ArcPy automated calculations that would otherwise be unmanageable. This workflow allowed our team to organize, analyze, and visualize data statewide, turning disparate data points into clear, actionable insights that directly inform prioritization efforts.<\/p>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"507\" src=\"https:\/\/uat.esri.com\/en-us\/industries\/blog\/wp-content\/uploads\/2025\/02\/Jypyter_2-1024x507.png\" alt=\"\" class=\"wp-image-561852\" srcset=\"https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Jypyter_2-1024x507.png 1024w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Jypyter_2-300x149.png 300w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Jypyter_2-768x380.png 768w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Jypyter_2.png 1296w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\"><em>The risk priority score method used to assign risk scores to each cesspool.<\/em><\/figcaption><\/figure>\n<\/div>\n\n<p class=\"undefined block-editor-paragraph\">The approach involved assessing each cesspool against 15 critical risk factors, each chosen to represent specific environmental, health, and infrastructural impacts. These factors included:&nbsp;<\/p>\n\n<ol class=\"wp-block-list\">\n<li>Distance to municipal or domestic drinking water wells<\/li>\n\n<li>Distance to domestic drinking water wells<\/li>\n\n<li>Intersection with well capture zones<\/li>\n\n<li>Distance to streams and wetlands<\/li>\n\n<li>Distance to coastline<\/li>\n\n<li>Intersection with projected sea level rise zones in 2030, 2050, and 2100<\/li>\n\n<li>Average annual precipitation<\/li>\n\n<li>Depth to groundwater<\/li>\n\n<li>Soil characteristics<\/li>\n\n<li>Cesspool density<\/li>\n\n<li>Coral cover<\/li>\n\n<li>Fish biomass\/recovery potential<\/li>\n\n<li>Coastline user-days<\/li>\n\n<li>Proximity to lifeguarded beach<\/li>\n\n<li>Coastal ocean circulation proxy<\/li>\n<\/ol>\n\n<p class=\"undefined block-editor-paragraph\">The HCPT scored each of Hawaii\u2019s 83,000 cesspools based on individual interactions between the cesspool and each of the 15 distinct risk factors. Every risk factor had to be geographically related to each cesspool point in a different way. These relationships included proximity to features such as drinking water wells or coastal areas; intersections between cesspools within a feature such as a well capture zone; and modeled parameters such as depth to groundwater. To account for cesspools located inland that still impact coastal waters, groundwater flow paths calculated with hydrologic models and digital elevation models (DEMs) were used to trace the most probable discharge location for each cesspool. This enabled the HCPT to determine which sections of the reef or coastal ecosystems were at risk of wastewater contamination. Each cesspool was then assigned a score for each risk factor, representing its relative impact on a given resource.<\/p>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"961\" src=\"https:\/\/uat.esri.com\/en-us\/industries\/blog\/wp-content\/uploads\/2025\/02\/Flowpaths-1024x961.jpg\" alt=\"\" class=\"wp-image-561882\" srcset=\"https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Flowpaths-1024x961.jpg 1024w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Flowpaths-300x281.jpg 300w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Flowpaths-768x720.jpg 768w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Flowpaths-1536x1441.jpg 1536w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Flowpaths-2048x1921.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\"><em>Groundwater flow path data was used to determine the impact of cesspools.<\/em><\/figcaption><\/figure>\n<\/div>\n\n<h2 class=\"wp-block-heading\" id=\"h-integrating-expert-insights-for-a-comprehensive-prioritization-framework\"><strong>Integrating Expert Insights for a Comprehensive Prioritization Framework<\/strong><\/h2>\n\n<p class=\"undefined block-editor-paragraph\">Each of the 15 risk factors was also assigned a specific weight based on its significance. Factors like proximity to drinking water sources were deemed more critical than others, such as proximity to recreational beaches. To establish these weights, the project team organized a series of workshops with experts from various fields, including coastal ecosystems, water resources, and wastewater management. During these sessions, experts discussed and assigned weights to reflect the relative importance of each factor. Between the workshops, a survey was distributed among the experts, soliciting a proposed score for each risk factor.&nbsp;<\/p>\n\n<p class=\"undefined block-editor-paragraph\">The score assigned to each risk factor was multiplied by its weight, and these weighted scores were summed to generate a single, comprehensive prioritization score for each cesspool. While this scoring system provided a high-resolution ranking for individual cesspools, comparing fractional differences in impact wasn\u2019t useful for management decisions. To streamline the process, cesspools were grouped geographically into census units\u2014tracts, block groups, and blocks. The average risk score for each census unit was calculated (excluding areas with few or no cesspools), reducing the data from 83,000 individual scores to less than 200 for tracts and a few thousand for blocks.<\/p>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"584\" src=\"https:\/\/uat.esri.com\/en-us\/industries\/blog\/wp-content\/uploads\/2025\/02\/Input_Data_App-1024x584.png\" alt=\"\" class=\"wp-image-561912\" srcset=\"https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Input_Data_App-1024x584.png 1024w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Input_Data_App-300x171.png 300w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Input_Data_App-768x438.png 768w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Input_Data_App.png 1426w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\"><em>The expert input data component of the HCPT, built with ArcGIS Web AppBuilder.<\/em><\/figcaption><\/figure>\n<\/div>\n\n<p class=\"undefined block-editor-paragraph\">These scores were further simplified into three priority zones: census units and their cesspools in the top quartile were classified as Priority 1, those in the second quartile as Priority 2, and the remaining two quartiles as Priority 3. This framework took over 1.3 million individual geographic relationships and distilled them into a straightforward, three-tier priority system, providing clear guidance for policymakers and managers in directing cesspool replacement efforts. Statewide, over 13,000 cesspools fall into high-priority zones.&nbsp;<\/p>\n\n<h2 class=\"wp-block-heading\" id=\"h-developing-interactive-hcpt-tools-for-stakeholders\"><strong>Developing Interactive HCPT Tools for Stakeholders<\/strong><\/h2>\n\n<p class=\"undefined block-editor-paragraph\">To make the HCPT accessible and useful for diverse users, from policymakers to residents, we focused on building a transparent and interactive platform. The goal was to provide not only the data, but also an intuitive, user-friendly interface to explore it. The framework and code base for the HCPT, including input data, the open-source scripts, and the output results, were deployed on GitHub, providing a permanent, open-access repository for archiving the process and for public viewing. However, because users need more than just shapefiles or static maps, we also utilized Esri\u2019s Web AppBuilder Developer Edition to create an interactive web viewer.<\/p>\n\n<p class=\"undefined block-editor-paragraph\">This platform enabled us to customize JavaScript libraries, allowing for essential adjustments such as nesting layers for cesspool points with each risk factor. This setup enables users to visualize both cesspool scores and the associated risk factor data together. We created two separate applications: one displaying prioritization scores within geographic census areas, and another showing all input risk factors with color-coded scores for each cesspool in relation to these factors.&nbsp;<\/p>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><a href=\"https:\/\/seagrant.soest.hawaii.edu\/app\/\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"642\" src=\"https:\/\/uat.esri.com\/en-us\/industries\/blog\/wp-content\/uploads\/2025\/02\/HCPT-Viewer-1024x642.png\" alt=\"\" class=\"wp-image-561922\" srcset=\"https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/HCPT-Viewer-1024x642.png 1024w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/HCPT-Viewer-300x188.png 300w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/HCPT-Viewer-768x481.png 768w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/HCPT-Viewer.png 1430w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\"><em>The public results app component of the HCPT, built with ArcGIS Web AppBuilder.<\/em><\/figcaption><\/figure>\n<\/div>\n\n<h2 class=\"wp-block-heading\" id=\"h-reaching-end-users-nbsp\"><strong>Reaching End Users&nbsp;<\/strong><\/h2>\n\n<p class=\"undefined block-editor-paragraph\">The HCPT is full of information ripe for decision-making, but its audience is composed of a wide spectrum of Hawaii\u2019s population. The tool was created for everyone from everyday homeowners to policymakers and expert researchers. In order to communicate the tool\u2019s findings, how it works, and its variety of uses, a website and series of videos were created. <a href=\"https:\/\/seagrant.soest.hawaii.edu\/cesspools-tool\/\">The site<\/a> serves as a literal and figurative entry point to the topic of cesspool conversion, supports consistent messaging, and provides a multimedia platform to educate the community about the impacts of nonpoint source wastewater pollution on human health and the environment. The site provides detailed instructions on how to navigate within the HCPT, as well as a succinct summary of the steps taken to determine priority areas.&nbsp;<\/p>\n\n<h2 class=\"wp-block-heading\" id=\"h-supporting-policy-community-outreach-and-workforce-development\"><strong>Supporting Policy, Community Outreach, and Workforce Development<\/strong><\/h2>\n\n<p class=\"undefined block-editor-paragraph\">The HCPT is beginning to play a key role in shaping state and local policies around cesspool replacement and wastewater management. The Hawaii State Department of Health (DOH) has used prioritization zones from the tool to set eligibility criteria for the Cesspool Pilot Grant Program (CPGP), ensuring that limited resources are allocated to cesspools with the highest risk to environmental and public health. Kauai County also adopted the tool as part of its $2 million cesspool conversion grant program. The HCPT was referenced in several Hawaii state legislative bills aimed at addressing cesspool remediation and replacement. The incorporation of HCPT into policy discussions highlights its value as a foundational resource for data-driven decisions and targeted funding for wastewater improvements. The tool is also being utilized by the US Environmental Protection Agency (EPA) Region 9 offices for its large-capacity cesspool mapping efforts, incorporating several layers from the HCPT into their own tool to support inspections and management briefings.<\/p>\n\n<p class=\"undefined block-editor-paragraph\"><strong><em>\u201cThe HCPT is a valuable tool for the State\u2019s Department of Health staff to assist with developing new policies regarding cesspools and conducting future outreach and education to communities. The HCPT was critical in identifying high-priority areas in the state where cesspools are adversely impacting the environment by contaminating our valuable drinking water resources, beaches, streams, wetlands, and coral reefs.\u201d<\/em><\/strong><\/p>\n\n<section class=\"news-blockquote--quote block-editor-quote is-layout-flow wp-block-quote-is-layout-flow\" aria-label=\"Quotation\"><blockquote class=\"news-blockquote-block--quote\"><div class=\"news-blockquote-block--author\"><cite class=\"author--name font-size-0 avenir-bold\"><\/cite><span class=\"author--info font-size--1 avenir-regular\">Sina Pruder, Former DOH Wastewater Branch Chief<\/span><\/div><\/blockquote><\/section>\n\n<p class=\"undefined block-editor-paragraph\">Local nonprofit organizations have even integrated the tool into community town halls and outreach events to engage the public on wastewater impacts and conversion needs. The HCPT project has fostered opportunities for the next generation of environmental data specialists. As a university-based project, the team incorporated numerous undergraduate internships that contributed to its development. Through hands-on research, these students gained valuable GIS skills.&nbsp;By supporting policymaking, community engagement, and skill building for future specialists, the HCPT is more than a mapping tool\u2014it\u2019s become a catalyst for change in how Hawaii approaches wastewater management and environmental resilience.&nbsp;<\/p>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"768\" height=\"1024\" src=\"https:\/\/uat.esri.com\/en-us\/industries\/blog\/wp-content\/uploads\/2025\/02\/Cesspool-3-768x1024.jpeg\" alt=\"\" class=\"wp-image-562012\" srcset=\"https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Cesspool-3-768x1024.jpeg 768w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Cesspool-3-225x300.jpeg 225w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Cesspool-3-1152x1536.jpeg 1152w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Cesspool-3-1536x2048.jpeg 1536w, https:\/\/www.esri.com\/en-us\/industries\/blog\/app\/uploads\/2025\/02\/Cesspool-3-scaled.jpeg 1920w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><figcaption class=\"wp-element-caption\"><em>A North Shore O\u2018ahu resident whose home and cesspool are exposed to beach erosion. Note the proximity of this cesspool to the shoreline. Photo credit: Shellie Habel.<\/em><\/figcaption><\/figure>\n<\/div>\n\n<h2 class=\"wp-block-heading\" id=\"h-looking-ahead-expanding-hcpt-s-capabilities-and-applications\"><strong>Looking Ahead: Expanding HCPT\u2019s Capabilities and Applications<\/strong><\/h2>\n\n<p class=\"undefined block-editor-paragraph\">For the first time, managers and homeowners alike have access to a clear visualization of cesspool pollution risks and the urgency behind the recommended upgrades, which can sometimes exceed $40,000. Building on this foundation, the HCPT\u2019s GIS capabilities offer exciting potential for future expansions, allowing for additional layers and datasets to enhance prioritization and decision-making. Hawaii\u2019s Act 217, passed in 2024, has provided our team with the opportunity to update the HCPT to include additional layers that cover planned and likely locations for centralized sewer upgrades. These additional datasets will provide homeowners\u2019 county managers with valuable insights when making costly infrastructure decisions.<\/p>\n\n<p class=\"undefined block-editor-paragraph\"><strong><em>\u201cAs part of Wastewater Alternatives and Innovations (WAI)\u2019s commitment to protecting Hawaii\u2019s water resources, we use the HCPT to strategically guide our outreach and legislative efforts. The tool allows us to identify high-impact cesspools and advocate for funding to support low- and moderate-income homeowners.\u201d<\/em><\/strong><\/p>\n\n<section class=\"news-blockquote--quote block-editor-quote is-layout-flow wp-block-quote-is-layout-flow\" aria-label=\"Quotation\"><blockquote class=\"news-blockquote-block--quote\"><div class=\"news-blockquote-block--author\"><cite class=\"author--name font-size-0 avenir-bold\"><\/cite><span class=\"author--info font-size--1 avenir-regular\">Gabby Saba Zimmer, WAI Program Manager and Instructor<\/span><\/div><\/blockquote><\/section>\n\n<p class=\"undefined block-editor-paragraph\">As a model for other regions facing similar water quality challenges, the HCPT demonstrates the critical role of GIS in supporting environmental health initiatives and informing public infrastructure planning. By identifying and prioritizing the areas most vulnerable to contamination, Hawaii is taking decisive steps toward a safer, healthier future, addressing this essential environmental issue with both efficiency and equity.<\/p>\n\n<p class=\"undefined block-editor-paragraph\">Learn More:&nbsp;<\/p>\n\n<p class=\"undefined block-editor-paragraph\"><a href=\"http:\/\/www.hawaiicesspooltool.org\">www.hawaiicesspooltool.org<\/a> or contact&nbsp;<a href=\"mailto:cshuler@hawaii.edu\">cshuler@hawaii.edu<\/a><\/p>\n\n<h2 class=\"has-text-align-center wp-block-heading\">Stay Connected with Esri&#8217;s Water Team<\/h2>\n\n<p class=\"has-text-align-center block-editor-paragraph\">ArcGIS is an extensive information system that enables modernization of workflows with easy-to-use applications for the field and office. Strengthen your organization with smart water solutions that will increase efficiency and provide insight for decision-makers. Visit the&nbsp;<a href=\"https:\/\/www.esri.com\/en-us\/industries\/water-utilities\/overview\" target=\"_blank\" rel=\"noreferrer noopener\">Esri Water Utilities<\/a>&nbsp;web site for more information.<\/p>\n\n<p class=\"has-text-align-center block-editor-paragraph\">Join the&nbsp;<a href=\"https:\/\/community.esri.com\/t5\/water-utilities\/ct-p\/water-utilities\" target=\"_blank\" rel=\"noreferrer noopener\">Water Utilities Community<\/a><\/p>\n\n<p class=\"has-text-align-center block-editor-paragraph\">Follow #EsriWater on social media:&nbsp;<a href=\"https:\/\/twitter.com\/EsriWater\" target=\"_blank\" rel=\"noreferrer noopener\">X<\/a>&nbsp;|&nbsp;<a href=\"https:\/\/www.linkedin.com\/groups\/6533227\" target=\"_blank\" rel=\"noreferrer noopener\">LinkedIn<\/a><\/p>\n\n<p class=\"has-text-align-center block-editor-paragraph\">Subscribe to the Water Industry newsletter \u201c<a href=\"https:\/\/www.esri.com\/en-us\/industries\/water\/water-news\" target=\"_blank\" rel=\"noreferrer noopener\">Esri News for Water Utilities and Water Resources<\/a>\u201c<\/p>","protected":false},"author":1062,"featured_media":0,"parent":0,"menu_order":0,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[5362],"tags":[287,2902],"class_list":["post-561752","blog","type-blog","status-publish","format-standard","hentry","category-wastewater","tag-gis","tag-wastewater","industry-wastewater"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v25.9 (Yoast SEO v25.9) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>How GIS Powers Hawaii&#039;s Cesspool Replacement Efforts<\/title>\n<meta name=\"description\" content=\"The University of Hawaii is using ArcGIS to prioritize replacing and upgrading cesspools at risk of contaminating water.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link 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