HISTORY
PIPELINE AND HISTORY Palo Verde’s wastewater pipeline unearthed significant artifacts en route to nuclear plant A BURIED PIPELINE THAT HAS QUIETLY CARRIED TREATED MUNICIPAL WASTEWATER FROM THE Phoenix area through Buckeye on its way to the Palo Verde Nuclear Generating Station unearthed archaeological history even as it became a cornerstone of the plant’s water strategy. BY DAVID KENNARD Designed and built when Palo Verde was sited hundreds of miles from perennial rivers and major reservoirs, the pipeline system was intended to supply huge volumes of water needed for condenser cooling, steam-cycle makeup and other plant functions without tapping scarce freshwater or groundwater. The project paired the nuclear plant’s owners — a consortium led by Arizona utilities — with municipal wastewater districts in the Phoenix metro area under long-term purchase contracts that laid out volumes, quality standards and pricing.
— and 10 smaller ones, indicating long-term settlement and daily activity in the area. More extensive excavations followed in the 1930s and 1940s, led by Phoenix-based archaeologist J. W. Simmons. Simmons focused much of his work on a massive trash mound and a cremation burial ground, uncovering evidence that provided key insights into Hohokam mortuary practices. At the heart of the site lies a low, flat area prone to flash flooding, making it unsuitable for permanent dwellings. Instead, the Hohokam built their homes on higher ground surrounding this basin, often near the middens that formed raised knolls. This layout aligns with known Hohokam settlement patterns, which favored elevated terrain along terraces. Simmons documented 63 burial pits and numerous pit houses, suggesting a densely populated community. The burial pits — typically about 20 inches in diameter and extending more than four feet underground — were used for cremations, with evidence indicating that the burning of the dead took place in the central lowland area. Although Simmons sometimes referred to himself as a “pothunter,” a term often associated with less scientific excavation, his work at the Van Liere Site demonstrated many hallmarks of professional archaeology. He approached the site with clear research questions, carefully documented his findings through photographs, maps, and notes, and maintained communication with leading scholars of the time. Among those he collaborated with were Emil Haury of the University of Arizona and A. V. Kidder, one of the most prominent archaeologists in the United States during that era. Like many archaeologists of his time, Simmons concentrated on burial areas due to the abundance of artifacts found in mortuary contexts. These discoveries contributed not only to understanding burial customs but also to broader questions about cultural interaction and historical timelines — topics that remain central to archaeological research today. Near the end of his life, Simmons donated much of the collection recovered from the site to the Buckeye Valley Museum, where many of the artifacts are still preserved and displayed for the public. Today, the Van Liere Site stands as an important window into the region’s ancient past, offering valuable insights into the daily life, traditions, and ingenuity of the Hohokam civilization.
PALO VERDE NUCLEAR POWER PLANT
BUCKEYE
Van Liere Ruins
Source: Buckeye Museum and APS
The Palo Verde Nuclear Generating relies on reclaimed water piped underground through significantly historic ground around Buckeye. Below: Arizona Public Service Company planners stand on ground in preparation for pipeline construction.
Water for the generating station
Public records show mostly routine incidents — leaks or breaks requiring repair and occasional contractual disagreements — rather than systemwide failures. Water managers and researchers treat Palo Verde’s pipeline as an influential early demonstration of “fit-for-purpose” reuse at industrial scale. Advocates say the project helped shape regional water-management thinking by showing that treated municipal effluent can supply heavy industrial consumers without compromising municipal needs or environmental protections. “That’s just a fact of what is in our water contracts and it is important to us to look for ways to operate more cost-effectively,” said Brad Berles, general manager of Palo Verde water resources in a 2022 news report for undergroundinfrastructure.com. Today, the pipeline continues to supply reclaimed water to Palo Verde under long- term contracts, with operators monitoring aging infrastructure and evolving regulatory standards.
Operators and municipal partners say one advantage of using treated wastewater is its steady year-round availability. Unlike runoff-fed supplies, effluent volumes relate more closely to population and indoor water use, making them relatively predictable even during drought. That predictability proved appealing for a baseload power plant that requires a continuous, controllable water supply. Over four decades, the pipeline system has been maintained and incrementally upgraded: pumps and controls modernized, pipeline segments repaired or relined as needed, and telemetry and SCADA systems added for remote monitoring. The reuse arrangement also attracted scrutiny at times. Regulators required monitoring and protocols to prevent cross-contamination and to ensure compliance with Clean Water Act and state rules; local concerns occasionally surfaced over odors, right-of-way impacts during construction or disputes about effluent allocation and rates in dry years.
Maria Johnson, Buckeye Library/Museum assistant shows some of the artifacts unearthed in the Liberty area and other archeological sites around Buckeye.
The delivered effluent met quality thresholds to prevent corrosion, scaling and biological growth in heat exchangers and condensers; additional on-site filtration and chemical treatment has been part of routine operations since startup.
rural unincorporated community of Liberty, where a large number of artifacts from a Historic Hohokam Village have been found. The significant archaeological site along the Liberty Canal sheds light on the lives and customs of the ancient Hohokam people, thanks to decades of exploration and excavation. Known as the Van Liere Site, the area was originally homesteaded in 1910 by Peter Van Liere. Bordered by the Southern Pacific Railroad tracks, the Buckeye Canal, and Jackrabbit Trail, the site stretches roughly three-quarters of a mile westward and sits atop what was once a thriving Hohokam village. The site first drew scholarly attention in 1928, when archaeologist Frank Midvale conducted an early survey. Although much of the land had already been leveled, Midvale identified at least five large trash mounds — known as middens
In a 2017 interview in Municipal Water Leader, Kathryn Sorensen, director of research at ASU’s Kyl Center for Water Policy and former Phoenix water director explicitly tied Palo Verde’s desert siting to availability of reclaimed municipal wastewater “The nuclear power plant … is able to exist in our desert environment only because of the availability of this reclaimed water,” Sorensen said. Construction in the late 1970s and early 1980s included large-diameter buried pipe, pump and booster stations, monitoring vaults and on-site storage and conditioning basins. Historic Hohokam Village at Van Liere site On its path westward through Buckeye, the pipeline runs almost exactly under the historic,
THE PIPELINE HISTORY
BEGINNING OF COMMERCIAL OPERATION
Water sources evaluated and tested effluent contract with SROG
Unit 1: January
Unit 3: January
1969
1973
1976
1986
1986
1988
Unit 2: September
Concept presented to Arizona Public Service Board of Directors
Initial construction permit, May
InBuckeye.com | May/June 2026
May/June 2026 | InBuckeye.com
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