Ladera Ranch water source at Diemer Water Treatment Plant 3972 Valley View Ave Yorba Linda sits on top of 2 old Shell oil wells owned by Aera Energy.

How can this be? There are historical oil wells associated with the Yorba Linda Oil Field surrounding the Diemer Drinking Water Treatment Plant in Yorba Linda, CA, it is part of the Brea-Olinda Oil Field operated by Aera Energy LLC. Ladera Ranch CA drinking water source is Robert B. Diemer Water Treatment Plant 3972 Valley View Ave Yorba Linda CA. It sits directly on top of 2 old Shell oil & gas wells that were plugged & capped in 1954 currently operated by Aera Energy LLC. One of the Shell oil & gas wells was drilled down to 4,199 feet and the other one was drilled down to 5,001 feet. Robert B. Diemer Water Treatment Plant is formally designated as a critical facility. Oil wells drilled before the 1970s often feature degraded steel casings and incomplete cement seals, creating direct vertical pathways for hydrocarbons, benzene, methane, or toxic formation brines to migrate up into foundations. Additionally, wells plugged prior to 1953 are not considered effective, even by industry standards.

Owned and operated by the Metropolitan Water District of Southern California (MWD), this 520-million-gallon-per-day facility serves as vital public infrastructure. It is responsible for treating and supplying clean drinking water to roughly 40% of Orange County, as well as parts of Los Angeles County. Abandoned Well Dangers: Millions of abandoned or "orphan" wells across the U.S. lack proper seals. While studies confirm these old wells leak methane, benzene (a known carcinogen), and heavy metals into air and groundwater, direct data on legacy PFAS leaks from century-old abandoned sites remains limited.

OK, here you go LA Times and CA-Post reporters, your show prep and detailed investigative research into the problems at Ladera Ranch are updated and ready for your next "exclusive"!

UNDERGROUND; There was no street location (address) when the Diemer Water Treatment Plant was built from 1961 to 1963 in Yorba Linda CA. The two deep drilled abandoned Shell oil wells under the Diemer Water Treatment Plant 3972 Valley View Ave Yorba Linda CA are only 794 feet apart on the same tract and appear to be directly under the water plant as per Cal-Gem oil finder website.  

One of the old Shell oil & gas wells is located near the front of the Diemer Water Treatment Plant in the ground, plugged and capped in 1954, it's API Number is 0405907797, it is located at Latitude Longitude coordinates 33°54'40.8"N 117°49'22.2"W.

The 2nd old Shell oil & gas wells located near the backside of the Diemer Water Treatment Plant in the ground, plugged and capped in 1954, it's API Number is 0405907798, it is located at Latitude Longitude coordinates 33°54'49.0"N 117°49'16.4"W.

One of the Shell oil & gas wells was drilled down to 4,199 feet and the other one was drilled down to 5,001 feet under the Diemer Water Treatment Plant 3972 Valley View Ave Yorba Linda.

OIL, IT'S DOWN THERE DRY HOLE OR NOT. In the Landman series Cooper hits it big by drilling deeper in existing oil wells that were designated as a dry hole, is this a real deal in the real oil man's world? Yes, this is absolutely a real-world practice. In the oil and gas industry the process is known as well re-entry or deepening by drilling down past the existing 2,000 to 4,000 feet or so. The core strategy of taking over old, shallow "dry holes" and drilling deeper to find untouched oil reservoirs is a classic, time-tested strategy used by independent oilmen and wildcatters. In the energy industry, a "dry hole" (or "duster") does not necessarily mean the ground has zero oil. 

Legally and commercially, a well is classified as a dry hole if it is incapable of producing oil or gas in sufficient quantities to justify the high cost of completing it at that specific depth, at that specific time. Many wells drilled decades ago, like in the 1920's and 1960"s, were vertical and relatively shallow—often stopping between 1,500 and 4,000 feet (just like on Citrus Lane and near Poets Park in Ladera Ranch). Older operators simply didn't have the technology, the high oil prices, or the geological data to know that an incredibly rich oil formation (like the Permian Basin's Wolfcamp Shale featured in Landman) sat just a few thousand feet deeper, sometimes down to 10,000 feet or more.

The more I dig into the mystery of the multiple Ewing sarcoma cancer cases and the old oil & gas wells under Ladera Ranch CA and possible water contamination, the more bizarre it gets. The supposed two 'Dry Hole' oil & gas wells under Ladera Ranch are not really dry. The original wildcatter drillers in the 1920's and 1960's just didn't go down deep enough to the shale layer where the oil is.

Robert B. Diemer Water Treatment Plant operated by the Metropolitan Water District of Southern California was built between 1961 to 1963 over two old Shell oil & gas wells from the 1950's, WTH? Metropolitan Water District treatment facility 3972 Valley View Ave Yorba Linda CA. Today the Diemer Water Treatment plant is formally listed as a "critical facility", but in 1961 when construction started it was not!

The water plant sits on a ridge high above Yorba Linda CA. The Robert B. Diemer Water Treatment Plant in Yorba Linda, CA sits at an elevation of approximately 800 feet above sea level. See all of the Cal-Gem well finder maps revealing the two Shell oil & gas wells on either side of the Diemer Water Treatment Plant, all the maps show the plant at 833 ft or 822 ft. The Google Earth search for 3972 Valley View Ave Yorba Linda CA also shows the plant at 805 feet, same place.

The two old Shell oil & gas wells under the Robert B. Diemer Water Treatment Plant 3972 Valley View Ave Yorba Linda were/are operated by the Aera Energy LLC. Aera Energy has owned most all of the oil and gas well infrastructure in the Yorba Linda area and has historically developed residential and golf course communities in the region. Aera Energy LLC helped develop the Black Gold Golf Club (seen in front of the Diemer Water Treatment Plant) as part of the master-planned Vista Del Verde community on the former oil field in Yorba Linda, California. Aera Energy LLC was/is part of Shell and Exxon-Mobil oil companies up until 2024.

LAWSUITS 2001 TO 2004; Aera Energy is depicted as "Shore Oil" in the 2019 American film, The Devil Has a Name, inspired by true events depicted in the pollution lawsuits by Starrh Farms. Aera Energy allowed 600 million barrels of oil wastewater to seep into the subsurface aquifers of the Starrh Farms after putting oil drilling waste into a mile of unlined percolation ponds near the farm.

Founded in 1997 as a joint venture between Shell and Exxon-Mobil, Aera Energy is one of California's largest oil and gas producers. Aera Energy LLC played a major role in developing Yorba Linda, California, by transforming an old oil field into a massive master-planned community, there are old abandoned oil wells everywhere underneath Yorba Linda CA. As oil production declined in the region, the Aera Energy company shifted from energy extraction to real estate development, introducing its first major project in the city in the early 2000's, just like Ladera Ranch. Aera Energy LLC knew all along that the two old Shell Oil Wells are/were under the Diemer Water Treatment Plant 3972 Valley View Ave Yorba Linda, they own them. Aera Energy LLC have/had annual revenues of over $3 billion dollars. 

News Article December 12th 2025; Thousands of gallons of oil and toxic wastewater poured out of a pipe running through a Monterey County oil field on Friday, Dec. 5, in the latest of several recent spills around the state. The pipe released 168 gallons of oil and nearly 4,000 gallons of toxic wastewater from drilling operations managed by Aera Energy at the San Ardo Oil Field, which sits near olive groves, row crops and ranches at the southern end of the county’s $5 billion agricultural region. The San Ardo Oil Field run by Aera Energy LLC is one of the most climate-polluting, carbon-intensive fields in the world.

SOLD OUT; In August 2022, IKAV, a European investment company, announced it was buying Aera from Shell and Exxon-Mobil. In July 2024, California Resources Corporation completed a $2.1 billion, all-stock purchase acquisition of Aera Energy.

The construction site selected in 1961 for the Robert B. Diemer Water Treatment Plant is located in the Chino Hills on a broad ridge perched 820 feet above the city of Yorba Linda, California. Building a critical drinking water treatment facility like the Robert B. Diemer Water Treatment Plant operated by Metropolitan Water District directly over two old 1950s Shell oil & gas wells is generally avoided due to severe structural, environmental, and contamination risks! 

The California Geologic Energy Management Division (CalGEM) enforces strict oversight under California Public Resources Code § 3208.1. Discovering a mapped legacy well under a drinking water treatment facility (actually 2 oil wells) requires costly re-abandonment (never done during construction of water treatment facility), extensive soil testing, and multi-year environmental impact reviews.

The more I dig into the mystery of the multiple Ewing sarcoma cancer cases and the old oil & gas wells under Ladera Ranch CA and possible water contamination, the more bizarre it gets. Today I discover that the water source for Ladera Ranch, the Robert B. Diemer water treatment plant, was built in 1961 on top of two old Shell oil & gas wells from 1954, both deep drilled to over 4,000 feet deep. The Robert B. Diemer Water Treatment Plant operated by the Metropolitan Water District of Southern California was built between 1961 and 1963, officially starting its operations in 1963. 

The two old Shell oil & gas wells that are located on either side (next to the building) of the Robert B. Diemer Water Treatment Plant were capped and plugged in 1954, there does not appear to be another re-abandonment of the two old Shell oil wells done during construction of the Robert B. Diemer Water Treatment Plant in 1961. The Yorba Linda Oil Field is an active petroleum and mineral resource area located in the Los Angeles Basin of Orange County, California. Formally discovered in 1930, with major development ramping up after 1937 and subsequent shallow pools found in the 1950s.

Shell Oil Company played a major role in developing the Yorba Linda Oil Field in Orange County, California, starting with extensive drilling operations following the area's early commercial development in 1937. Shell Oil was one of the primary major operators alongside independent drillers during the 1940s and 1950s in Yorba Linda CA.

The Robert B. Diemer Water Treatment Plant supplies treated water to south Orange County through the South Coast Water District and regional distribution systems like the El Toro Water District, serving agencies and communities such as: Ladera Ranch, Dana Point,
Laguna Beach, (including South Laguna), Lake Forest, Mission Viejo, San Clemente and San Juan Capistrano. Orange County, California has the highest rate of overall cancer incidence for people under 50 compared to surrounding Southern California counties. Orange County has the highest overall rate of cancer incidence in people under 50, compared to Los Angeles, Riverside, San Diego and San Bernardino counties. 

Both puzzling and concerning, the increase in cancer rates among younger adults is linked to several possible causes. A 2026 study analyzing data from the California Cancer Registry examined youth (ages 0–19) and found that prenatal proximity to active and inactive oil wells was associated with increased risks of specific pediatric and young adult tumors, including medulloblastoma and germ cell tumors.

OK, here you go LA Times and CA-Post reporters, your show prep and detailed investigative research into the problems at Ladera Ranch are updated and ready for your next "exclusive"!

In the 2025 water report from Metropolitan Water District via the Santa Margarita Water District (SMWD), they state, organic chemical contaminants, including synthetic and volatile organic chemicals, that are by-products of industrial processes and petroleum production and can also come from gas stations, urban stormwater runoff, agricultural application, and septic systems could be in the SMWD drinking water, they uses chloramines to neutralize the petroleum by products. The Maximum Contaminant Levels (MCL) for BTEX (benzene, toluene, ethylbenzene, and xylenes) in California drinking water are 1 ppb for benzene, 150 ppb (or 0.15 mg/L) for toluene, 300 ppb (or 0.3 mg/L) for ethylbenzene, and 1,750 ppb (or 1.75 mg/L) for xylenes.

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The Crude Oil Blind spot: Water-soluble components of crude oil—such as toxic BTEX compounds (Benzene, Toluene, Ethylbenzene, Xylenes)—dissolve completely in water. Because they do not form suspended droplets, they can remain highly concentrated in water that appears completely clear and yields a low NTU reading. Ladera Ranch CA Drinking Water Source is Robert B. Diemer Water Treatment Plant in Yorba Linda CA, It Sits on Top of 2 Old Shell Oil Wells that were plugged and capped in the 1950's, this never should have happened.

Large regional water wholesalers like the Metropolitan Water District of Southern California (MWD) (which supplies water to 19 million people) utilize a strict 5-step process. Following the conventional treatment process, chlorine and ammonia are added to the water to form chloramines and maintain a disinfectant residual in the distribution system.  

The Robert B. Diemer Water Treatment Plant, located at 3972 Valley View Ave, Yorba Linda, CA, is a primary drinking water source for south Orange County communities, including Ladera Ranch. Operated by the Metropolitan Water District of Southern California (MWD), the 200-acre facility cleans imported water from the Colorado River Aqueduct and the State Water Project before distributing it via the Allen-McColloch Pipeline to locations south. The Santa Margarita Water District (SMWD) receives imported treated drinking water for Ladera Ranch from the 26-mile Allen-McColloch Pipeline operated by the Metropolitan Water District of Southern California from the Robert B. Diemer Water Treatment Plant in Yorba Linda.

Prestressed Concrete Cylinder Pipe (PCCP) that carries the drinking water to Ladera Ranch CA cannot reliably withstand direct exposure to oil and gas from an underground leaking well. The Allen-McColloch Pipeline (AMP) is a critical 26-mile regional water transmission artery that flows downhill from the Robert B. Diemer Water Treatment Plant in Yorba Linda. Operated by the Metropolitan Water District of Southern California, this buried pipeline serves as the primary backbone for delivering clean, imported drinking water to Ladera Ranch in Southern Orange County. Water flows by gravity from the hills of Yorba Linda all the way south. The Allen-McColloch Pipeline terminates at the El Toro Reservoir in Lake Forest. From the El Toro Reservoir (33°37'24.2"N 117°39'56.2"W) and from regional junctions, wholesalers like the Municipal Water District of Orange County (MWDOC) and local retail providers (such as the Santa Margarita Water District, which serves Ladera Ranch) pump and distribute this water to homes and businesses across the south county grid. Pipeline Diameter: Varies between 54 to 78 inches along its southern portions. Composition: Constructed primarily using Prestressed Concrete Cylinder Pipe (PCCP). Prestressed Concrete Cylinder Pipe (PCCP) is a heavy-duty composite pipe made from a mix of concrete, a thin steel core, and high-tension steel wire designed to transport water and wastewater under high pressure. 

The Prestressed Concrete Cylinder Pipe that handles the drinking water from from Diemer Water Treatment Plant to end point El Toro water reservoir has been under ground for about 60 years.  This pipe combines the compressive strength of concrete with the tensile strength of steel, it is most commonly buried down in the dirt at least 2 feet deep from surface. NOTE* Prestressed Concrete Cylinder Pipe (PCCP) cannot reliably withstand direct exposure to oil and gas from an underground leaking well. While the dense concrete and inner steel cylinder are highly durable against basic environmental loads, they are not designed to serve as a barrier against raw hydrocarbons, volatile organic compounds (VOCs), and corrosive oilfield brines. Old oil wells rarely leak just oil and gas; they usually discharge highly corrosive produced water containing high concentrations of chlorides (salts), sulfides, and organic acids. Once hydrocarbons and acidic oilfield brines penetrate the outer mortar coating, they destroy the alkaline environment that naturally protects the steel. Exposure to hydrogen sulfide (H₂S) or acidic fluids can induce hydrogen embrittlement or sulfide stress cracking in the highly stressed wires.

Concern over Cancer and Old Oil & Gas Wells at Ladera Ranch CA Needs Focus on Sewer System Built on Top of Decaying Well 8,365ft Under Merriweather Pl right near Poets Park. The so called re-abondonment of the decades old oil well at/under Poets Park on July 19, 2001 during construction of the Ladera Ranch community is bogus. Paul Frost engineer and rep for DOGGR was at the Poets Park Ladera Ranch CA job site from 9:30 am to 10:30 am on Thursday July 19, 2001. Paul Frost called DOGGR home office in Sacramento CA at 10:30 am to get an ok to close the well by plugging the well from 351 feet up to the surface, as they could not get past an obstruction at 351', leaving the other 8,014 feet to the bottom open to the elements and most likely leaking.

Thomas M. Walker an independent petroleum consultant and senior reservoir engineer in California was working (paid) as the rep for DMB Ladera LLC and was overseeing the re-abandonment project (that was stuck at 351') of the old Exxon Mobil oil & gas well that was drilled down to 8,365' (in 1961) on Thursday morn July 19, 2001 near Poets Park, Walker was there with DOGGR rep/engineer Paul Frost. A DOGGR directive required cement to be squeezed past the blockage at 351 feet on outside of casing down to bottom of oil well to protect the lower 8,014 feet, it was not done according to site reports filed by Paul Frost rep for DOGGR at Poets Park Ladera Ranch CA. 

An old oil and gas well located underneath a community's sewer system can cause significant health and safety problems. The "Highway Effect" of Sewer Lines: Underground sewer pipes sit in trenches backfilled with loose, porous gravel and soil. If a deep oil well leaks gas upward, the gas will take the path of least resistance. It can penetrate cracked sewer pipes or travel horizontally along the loose soil surrounding the plumbing network, distributing toxins right into neighborhood properties. Old wells frequently leak benzene, hydrogen sulfide (H₂S), and other volatile organic compounds (VOCs).

If the steel casings of the decades old 1961 deep drilled  Exxon Mobil oil & gas well under Merriweather PL near Poets Park in Ladera Ranch CA has crumbled and released crude oil or methane/benzine gas into the sewer system there will be severe health problems. A 1960's era deep drilled oil & gas well is right under the SMWD sewer system at Poets Park, Ladera Ranch and there is a 1920's era deep drilled oil & gas well under the SMWD sewer line at Citrus Lane Ladera Ranch with notations to NOT build over this well. Crude oil intrusion into a sewer system can cause significant human health problems. 

Whether the entry occurs through a ruptured underground pipeline, an accidental industrial leak, or illegal dumping, mixing crude oil with wastewater infrastructure poses both immediate and long-term medical risks. Crude oil contains volatile organic compounds (VOCs) like benzene, toluene, and xylene. Because sewer systems connect directly to homes and businesses via plumbing vents and drains, these hazardous gases can travel up pipelines and enter indoor living spaces. Children, the elderly, and individuals with asthma or pre-existing respiratory conditions are highly susceptible. Chronic exposure to chemicals found in crude oil, specifically benzene, is known to cause leukemia and other cancers under California Proposition 65 guideline.

Ladera Ranch Drinking Water Stored Underground in Concrete Tanks at Mission Hills Park 29361 Bell Pasture Rd Ladera Ranch, CA, nearby (less than a mile underground) at Citrus Lane a 105 year old Union oil & gas well could be leaking horizontally into foundations. When and if the 105 year old and 64 year old oil & gas wells at Citrus Lane and Poets Park Ladera Ranch CA start leaking, fluids and gases typically migrate both vertically up the compromised wellbore and horizontally, lateral side to side, into surrounding soil, rock layers and into concrete foundations of nearby structures. Degraded steel casing and crumbling historic cement plugs allow methane gas and H2S gas and liquids to travel straight up the old pipe path and horizontally. 

Sat July 25, 2026, This so called re-abondonment of the decades old oil well at/under Poets Park on July 19, 2001 is bogus. Paul Frost engineer and rep for DOGGR was at the Poets Park Ladera Ranch CA job site from 9:30 am to 10:30 am on Thursday July 19, 2001. Paul Frost called DOGGR home office in Sacramento CA at 10:30 am to get an ok to close the well by plugging the well from 351 feet up to the surface, as they could not get past an obstruction at 351', leaving the other 8,014 feet to the bottom open to the elements. "Evidence now, theories later" my independent investigation of rare cancer cluster in Ladera Ranch CA and two abandoned oil & gas wells deep drilled thousands of feet underground that I published today about 'not building over' the poorly re-capped wells in July 2001 by DMB Ladera LLC the developer of the $100 million dollar project.  

 

Sarasota Private Investigator Bill Warner, True Crime Stories, Bill Warner Investigations Sarasota Fl.