How SJWD resolves 90% of after-hours calls with AI Voice Agent
"Before Aircall’s AI Voice Agent, our treatment plant operators were taking billing calls at 2 AM while trying to manage water quality."
This is when Jeff Diaz, Chief Information Services Officer at SJWD Water District, knew something had to change. A leader known for balancing innovation with customer care, Diaz wanted to protect both his team’s time and his community’s experience.
SJWD Water District is a regional water utility serving 36,000 service connections across South Carolina, treating 8-9 million gallons daily for nearly 90,000 residents. As the utility expanded from its 1956 roots serving rural textile communities, communication demands grew exponentially.
The challenge
SJWD faced a critical bottleneck in their 24/7 operations. With treatment facilities running around the clock, skilled water treatment operators were fielding customer service calls during overnight hours.
"We had treatment plant operators at 2 o'clock in the morning answering billing questions for customers," Jeff Diaz explained. For him, this wasn’t just an operational issue—it was a sign that customers weren’t getting the service they deserved, and that staff were being pulled away from critical water treatment duties to handle routine customer inquiries.
A single after-hours phone line couldn’t keep up with growing volumes. This increasing volume was leading to longer wait times for customers seeking timely updates or reassurance, especially during emergencies when call spikes were inevitable.
Moreover, the pressure was amplified by language barriers. While SJWD serves a large Spanish-speaking population, after-hours support was limited to English, leaving a segment of the community underserved.
The turning point
In 2024, Hurricane Helene was a turning point for SJWD's customer communication strategy. When cell towers went down and traditional phone access for some staff members disappeared, it became clear that the utility needed resilient systems that could maintain customer connection during crises.
"We had language barriers, escalating weather events, and then a serious hurricane where our staff had no cell phone access. That showed us the importance of having technology in place to give customers a touch point—even if it’s not the full experience they usually get, at least they can get updates and some information."
Jeff Diaz realized that explosive growth in their service area—now at nearly 90,000 residents today—meant they needed scalable solutions beyond simply hiring more customer service representatives. As both a technologist and a customer advocate, he knew their next step had to protect staff time while improving accessibility for every resident. The decision crystallized around two core needs: protecting critical operations staff from routine interruptions and ensuring 24/7 accessibility for their diverse customer base during both normal operations and emergencies.
The solution
SJWD chose Aircall's AI Voice Agent to transform their after-hours customer service approach. Having used Aircall’s customer communications platform since 2022 to replace a legacy phone system, the company was already confident in the platform’s reliability for remote work and valued the deeper visibility it provided through features like call tagging, transcription, and performance tracking.
Jeff Diaz implemented a methodical testing process, analyzing call logs to identify the most common after-hours inquiries. "I started looking at their call logs, what are the pain points, what are customers asking for when they're calling in after hours," he explained.
The team created two AI agents: Eve for English-speaking customers and Vespera for Spanish-speaking customers, each programmed with detailed responses about reconnection policies, account setup procedures, and water quality concerns.
Crucially, the team ensured the scripts reflected SJWD’s service culture—professional, respectful, and customer-first.
"When I saw customers talking with the agent saying ‘yes ma’am, thank you ma’am,’ I knew they felt they were in a conversation, and that was an important aspect of it."
For Jeff, that was the true measure of success: not just resolving calls faster, but making sure customers felt heard—even when speaking with AI. His diligence in reviewing transcripts became a way to hold the system accountable and ensure it lived up to SJWD’s customer-first standards.
The results
The transformation exceeded expectations, with AI Voice Agent now handling the majority of after-hours customer inquiries.
Key results:
~10% of inbound calls handled by AI Voice Agent
~90% of after-hours calls successfully resolved by AI Voice Agent
Decreased average resolution time from 150 sec to 55 sec
24/7 bilingual customer support capability
Immediate relief for treatment operators, enabling full focus on water quality and system safety
The remaining ~10% of after-hours calls that do require human intervention are predominantly emergencies or complex billing issues requiring PCI compliance measures.
Most customers found it easy and effective to engage with the AI voice agents. To keep that experience consistent, Jeff and his team thoroughly review call transcripts, both to monitor service quality and to identify opportunities for improvement. Customers respond politely and naturally, often treating AI Voice Agent as though it were a live agent. One team member even asked if the Spanish-speaking agent was from Colombia, impressed by its conversational flow.
“Customer feedback has been generally very positive. Before this, after-hours calls were handled by one desk, one phone. Now, Eve can talk to two or three people simultaneously if we’re having a major main break or a boil water advisory. So, it has definitely improved the [customer] experience.”
Beyond efficiency, the system also delivers valuable operational insights. Call transcripts help SJWD identify service patterns and geographic clustering of issues, sometimes highlighting leaks or pressure problems before they escalate.
Looking ahead
SJWD plans to expand AI Voice Agent capabilities to serve additional languages, ensuring greater accessibility for their increasingly diverse community. They are also exploring deeper integrations with internal systems to further streamline customer interactions.
Advice to others
For companies considering similar technology for customer communications, Jeff Diaz stresses the importance of involving all stakeholders early and setting clear expectations. The key, he says, is to position AI as a supportive tool rather than a replacement.
“[AI] helps and it augments—there’s no replacement here. We’re just trying to make people as good as they can be at their jobs. AI is one piece of the puzzle, and the sooner teams get comfortable working with it, the better.”
By framing AI as an augmentation to human expertise, SJWD has managed to build excitement rather than resistance. Diaz’s leadership kept the utility’s culture firmly human-centered, ensuring that technology serves people—not the other way around.
Ready to transform your after-hours customer service without expanding your team? Discover how AI Voice Agent can handle routine inquiries while your staff focuses on critical operations.