Diamond Shamrock was one of the major oil-refining and marketing companies in Texas in 1993, with more than 6,000 employees and over $2.5 billion in revenue. It traces its origins back to three companies: Diamond Alkali, Shamrock Oil and Gas, and Sigmor Corporation. A group of glass manufacturers founded Diamond Alkali in Pittsburgh, Pennsylvania, in 1910 to produce soda ash, an important component in the glass industry. A large industrial plant was built at Painesville, Ohio, in 1912, and in the 1920s, under the leadership of T. R. Evans, Diamond Alkali developed into an important chemical company. It diversified into the production of calcium carbonates, coke, cement, chlorine, and a variety of other products. Under the presidency of T. R.'s son, Ray Evans, the company moved to decentralize after World War II.qv In 1946, in Deer Park, Houston, Texas, construction was started on a new plant to produce chlorine and caustic soda. Diamond Alkali changed its headquarters from Pittsburgh to Cleveland, Ohio, in 1948. A third plant was erected in Muscle Shoals, Alabama, in the 1950s, and Diamond Alkali further extended its range of products into plastics and agricultural chemicals. In the 1960s the company opened another facility in Delaware City, Delaware, and purchased several additional chemical companies, including the Chemical Process Company of Redwood City, California, and the Nopco Chemical Company of New Jersey. In spite of its growth, Diamond Alkali feared absorption by a larger chemical firm or by one of the major oil conglomerates, and in 1967 it merged with Shamrock Oil and Gas of Amarillo to increase its corporate strength.

The second progenitor of Diamond Shamrock, the Shamrock Oil and Gas Company, was founded on August 9, 1929, by John Sheerin, who named the company for a symbol of his native Ireland. The company was headquartered in Amarillo and financed by the Fownes family of Pennsylvania. In its early years Shamrock Oil and Gas lost some $9 million. Its first refinery was built in 1933 at Sunray, in Moore County, Texas, and that same year the company opened its first gas station, also at Sunray. In 1938 James Harold Dunn,qv a young engineer at the Lone Star Gas Corporation, joined Shamrock Oil and Gas as vice president and general manager, and the next year the company made its first small profit. In 1939-40 Shamrock and the Lone Star Gas Corporation jointly built a plant at Murchison in Henderson County to recycle natural gas. By 1941 there were 162 Shamrock service stations in the southwestern states. During the mid-1940s Shamrock became a major producer of natural gas. The company paid its first dividend in 1943, and was listed on the New York Stock Exchange in 1944. Dunn became company president in 1945 and served in that post for ten years; he was succeeded by C. A. Cash in 1955. In 1959 Shamrock opened its first catalytic cracking unit at the McKee complex at Sunray.

In 1960 Shamrock Oil and Gas increased the number of stations using its gasoline by purchasing much of the Sigmor chain of service stations-the third major component of the modern Diamond Shamrock Corporation. Sigfried (Sig) Moore operated the Midway chain of stations in the 1930s and 1940s. When, in 1943, Moore loaned one of his employees, Thomas E. Turner, the money to start up a business of his own, Turner adopted the name Sigmor for the chain of stores he built up in the 1940s and 1950s. Sigmor was incorporated in 1952, then restructured in 1959 so that each station could incorporate individually. Most of the Sigmor chain was purchased in 1960 by Shamrock, which then leased it back to Turner, who continued to run it. In the 1960s Shamrock expanded its production facilities at McKee and constructed pipelines throughout the Southwest.

In 1967 Shamrock Oil and Gas Company and Diamond Alkali merged to form the Diamond Shamrock Corporation. At the time of the merger, the products of the company were about 20 percent oil and gas and 80 percent chemical. The company expanded its oil and gas exploration efforts in the early 1970s and built several new chemical plants, including the Battleground plant in Houston. In 1978 the company headquarters were moved to Dallas. That same year Sigmor purchased its stations back from Diamond Shamrock, though it continued to market Diamond Shamrock products. In 1980 Diamond Shamrock employed some 12,400 people in thirty-seven countries and was a leader in energy, technology, and chemical markets.

In January 1983, Sigmor, by then one of the largest independent service-station chains in the country, merged with Diamond Shamrock. Diamond Shamrock acquired some 600 retail outlets by the merger, as well as the Three Rivers oil refinery, constructed by Sigmor in the mid-1970s in Live Oak County midway between San Antonio and Corpus Christi. In 1987 the Diamond Shamrock Refining and Marketing Company was separated from Diamond Shamrock Corporation, the parent company, and became an independent company headquartered in San Antonio. As part of the same reorganization, Diamond Shamrock Corporation changed its name to Maxus Energy Corporation, and severed all legal ties to Diamond Shamrock Refining and Marketing Company. In 1990 Diamond Shamrock Refining and Marketing Company, Incorporated, simplified its name to Diamond Shamrock, Incorporated. In 1993 Diamond Shamrock operated two major petroleum-refinery complexes: the Three Rivers plant and the McKee complex at Sunray. The two complexes had a combined capacity of nearly 200,000 barrels a day. An extensive network of some 4,400 miles of company-owned pipelines connected the refineries to supply points and markets in Texas, Colorado, New Mexico, and Oklahoma. Some 2,000 outlets carried the Diamond Shamrock brand, including 776 company-operated Corner Stores in Texas, Colorado, Louisiana, and New Mexico.

BIBLIOGRAPHY: J. Evetts Haley, Story of the Shamrock (Amarillo: Shamrock Oil and Gas Corporation, 1954).


Diamond Shamrock in 1984 agreed to clean up its dioxin-contaminated New Jersey plant. The next year low energy prices forced the company to post losses of $605 million.

1985 Fermente Plant ProtectionSDS Biotechを購入
The Diamond Alkali Co. Site occupies about 1 acre immediately adjacent to the Passaic River, in Newark, Essex County,
New Jersey. From 1943 through 1968, the company manufactured numerous chemicals on the site, including 2,4,5-trichlorophenol,
which is likely to contain dioxin as an impurity. Extensive sampling conducted by EPA and the State has detected extremely high
concentrations of dioxin on and off the site.
EPA and the State have covered the area of major contamination with plastic tarpaulins. Adjacent transportation routes
and residential areas were swept and vacuumed. Workers may have been exposed to dioxin during normal operations,
as well as during renovations conducted during the summer of 1982. Another company has since purchased the land.


Revisiting Love Canal
April 26, 2004

Finally, travel to 'Love Canal' on Newark Bay, to a derelict factory in the Portuguese working-class section of Newark,
on a Passaic River bend. Here in the '60s,
Diamond Alkali Company (renamed Diamond Shamrock) made Agent Orange,
the herbicide that disabled thousands of U.S. GIs, (some compensated by the Pentagon), plus many more Vietnamese peasants
(never compensated).

In 1992, investigators revealed that Diamond's Newark plant knowingly contaminated its personnel with dioxin, the deadliest
of synthetic chemicals. Workers were disfigured. Others sickened and died. Though more responsible chemical corporations
eliminated dioxin from their manufacturing waste, Diamond did not, since that would have slowed production.

Instead the company in a sense "launched" Agent Orange as a weapon against the citizens of Newark. A deadly dioxin cocktail
formed a perpetual slippery film on the factory floor. "Every other week or so" workers were ordered to hose the floors with
sulfuric acid. The poison flowed into trenches, into the Passaic River, and eventually to Newark Bay and beyond.

So much toxic waste went through the plant's industrial sewer that it formed a reef in the river. Employees were directed to
surreptitiously wade in, and with shovels "chop up" the toxic deposits so the reef wouldn't attract attention.

In 1983, New Jersey discovered the contamination, shut the factory, and Republican Gov. Tom Kean declared a state of
emergency. Regulators rushed to vacuum poisoned city streets, capped 10,000 cubic yards of deadly waste, fenced the plant
and posted a 24-hour guard. Both the factory and Passaic River were declared federal Superfund sites, though the EPA did
nothing to clean up the waterway.

In 1986, Occidental bought Diamond Shamrock, knowing that under Superfund Law, the purchase made it liable for the river
cleanup. But though the company collected Diamond's profits, it stonewalled on the Passaic, using the same winning strategies
it learned at Love Canal. And still the EPA did nothing.

When the blue-collar community of Love Canal, N.Y, saw its children sicken at a terrifying rate and learned that its homes were
built beside a toxic waste dump. Residents pleaded for government help, but aid was slow in coming. Polluter
Hooker Chemical
stalled the regulatory machinery. Its lawyers denied the science that linked deadly waste to dying children, and the company
avoided full payment for cleanup until 1995.

Newark Bay, November 2003.
Three conservation organizations announce plans to sue polluter
Tierra Solutions within 90 days, for what the groups say is the
worst case of in-water dioxin pollution in the United States
-- maybe the world.

Both Hooker Chemical and Tierra Solutions, it turns out, are subsidiaries of the same hydra-headed monster:
Occidental Petroleum, one of the planet's most heinous polluters.

It donates to electable politicians from both parties and gets huge returns on investment, no matter who wins. ・・・
The political favors Occidental gains from these gifts keep it well subsidized by government -- and insulated from prosecution
for harm done to the environment and public health in the United States and globally.


Smelling blood, corporate raider T. Boone Pickens made a hostile takeover bid for Diamond Shamrock in 1986.

In defense, it spun off its refining and marketing arm, which retained the Diamond Shamrock name, and the exploration and production company changed its name to Maxus. (Maxus was bought by Argentine oil firm YPF in 1995.) The new Diamond Shamrock, based in San Antonio, went public in 1987.

1986年 オキシデンタル・ケミカル・コーポレーション(Occidental Chemical Corporation)

The company entered the petrochemicals business two years later and in the 1990s added refineries, expanded pipelines, and increased retail gasoline outlets in the Southwest. It splashed out $260 million in 1995 to acquire 661 National Convenience Stores in Texas.

The next year the company merged with Ultramar to form
Ultramar Diamond Shamrock.

Ultramar was founded in 1935 as Ultramar Exploration Co. Ltd. by four South African gold mining concerns (including Consolidated Gold Fields) to develop Venezuelan oil fields. The company, which worked closely with Texaco, changed its name to Ultramar Co. Ltd. in 1940. It began oil exploration and marketing operations in Canada in the 1950s and marketing operations in the US and Europe in the 1960s. By 1975 Ultramar owned 1,100 gas stations in eastern Canada. During the 1980s oil slump, it struggled and was forced to sell its UK marketer, Ultramar Golden Eagle.
LASMO, a UK oil company, bought Ultramar for about $3.2 billion in a hostile takeover in 1991. The next year LASMO spun off the North American refining and marketing operations as Ultramar Corp. -- the company that ultimately joined with Diamond Shamrock.

In 1997 the new Ultramar Diamond Shamrock acquired Total Petroleum (North America) from TOTAL, bringing it three refineries and some 2,000 gas stations.

As the oil market took a turn for the worse, Ultramar Diamond Shamrock agreed in 1998 to combine its Canadian operations with Petro-Canada, then scrubbed the deal because of Canadian regulatory opposition. It also contracted PG&E to manage its energy purchases and reduce its energy costs over seven years. That year it began a restructuring plan to divest underperforming assets, including 239 convenience stores.

President Jean Gaulin succeeded Roger Hemminghaus as CEO in 1999 (Gaulin became chairman in 2000; Hemminghaus, chairman emeritus). That year the company's plans to merge its operations with those of Phillips Petroleum were called off after the two could not agree on terms. To retrench, it sold its marketing and transportation operations in Michigan to Marathon Ashland Petroleum, but had to close a 50,000-barrel-a-day refinery in Alma, Michigan, because no buyer could be found.

In 2000 Ultramar Diamond Shamrock agreed to buy Tosco's Avon refinery in California for $650 million.



New York Times April 13, 1989

Dioxin Ruling In New Jersey

A New Jersey judge has ruled that insurance companies do not have to pay for a $25 million dioxin cleanup at the site of a former Diamond Shamrock plant but must make payments to a fund for Agent Orange victims.

New York Times 1991/12/3

Dioxin and Former Maker Go on Trial

A long-anticipated trial pitting scores of local residents against the Diamond Shamrock Corporation, which manufactured Agent Orange here in the 1950's and 60's, opened today with a lawyer for the plaintiffs arguing that the company had recklessly endangered the health of its workers and knowingly exposed residents and businesses near its plant to the potentially harmful effects of dioxin. But the defense contended that Diamond Shamrock had acted reasonably and countered that there was no proof that dioxin, an unwanted byproduct of Agent Orange and other herbicides, harmed any of the plaintiffs.


New York Times August 15, 2006

The Occidental Petroleum Corporation's Occidental Chemical Corporation said it had sold a process chemicals division to Henkel Group of Dusseldorf, West Germany. Terms were not disclosed. Occidental had acquired the division as part of its purchase of Diamond Shamrock Chemicals in September 1986. The division, which had sales of about $160 million last year, makes specialty industrial chemicals. People within the chemical industry said the price of the transaction was slightly less than $200 million.