Are US Dams Safe?

Dam disasters have been rare but spectacular.

The recent scare at the Oroville Dam in California has brought dam safety to public attention. The following is adapted from a piece by Jeremy P. Jacobs.


The catastrophic failure of the South Fork Dam in 1889 killed more than 2,200 people in Johnstown, Pennsylvania.

There have been many U.S. dam failures. And some have been catastrophic.

In May 1889, the 72-foot-tall South Fork Dam on western Pennsylvania’s man-made Lake Conemaugh gave way, unleashing a 40-foot wall of water that hit the city of Johnstown, nearly 9 miles away. More than 2,200 people were killed–that’s 1 out of every 5 Johnstown residents.

And in California, the St. Francis Dam was considered an engineering feat in Los Angeles County until it failed in 1928, killing as many as 400 people.

The Baldwin Hills Dam, also in Los Angeles, gave way, killing five in 1963. In 1976, the Bureau of Reclamation’s Teton Dam in eastern Idaho collapsed, killing 11 and causing more than $1 billion in property damage.

The most recent dam failure to cause a fatality occurred in 2006, when the earthen Ka Loko Dam in Kauai, Hawaii, breached, killing seven people.

Some experts caution against making too much of the number of fatalities linked to dam failures.

Martin McCann of Stanford University’s National Performance of Dams Program said that since the 1850s, dams have killed probably a little more than 4,000 people — a large number, but one that pales in comparison to auto accidents, for example.

“If your argument were to be based on body counts, crocodiles and deer running on highways might beat out dams,” McCann said.

He noted that dam inspections and state and federal authorities have improved, especially since the 1970s when fatalities from dam failures peaked at more than 450 in the decade.

“It’s not black and white. Do we have a lot of dams that pose a risk to the public? Yeah, we do,” he said. “Are they all in terrible shape? Not even close.”

Reference source:  E & E News.

Current Water News

by Hardly Waite

Water Litigation

In the ongoing state vs. state water wars being waged in the courts, Georgia won a major decision hardly4over Florida and Texas won over New Mexico. Both cases involve the right to water in rivers that pass through both states.


In a more complex litigation about water, the Trump administration (as did also the Obama administration) is asking a federal court to dismiss a lawsuit by New Mexico and the Navajo Nation over a 2015 mine-waste spill caused by the Environmental Protection Agency (EPA) at the abandoned Gold King Mine in Colorado.  There are 1.2 billion in claims, and the government is denying responsibility because the agency was simply aiding in cleanup caused by operators of the mine. Republicans earlier slammed the Obama administration for taking the same stance as the current administration.


The 2015 spill was caused by an EPA contractor who, working with federal and state employees, miscalculated the pressure of wastewater at the abandoned mine. About 3 million gallons of toxic sludge spilled out, turning the Animas River orange for days, along with downstream rivers that run through New Mexico and the Navajo Nation’s reservation.

New Mexico has also sued Colorado in the Supreme Court over its alleged responsibility for the spill. The high court is considering whether to hear that case.


Other Water News

New York city’s need for water infrastructure upgrade is expected to cost $80 billion over the next 20 years.


Oklahoma is considering joining the practice of several other states of storing water underground by using “leaky ponds” to recharge aquifers. Rather than allow surplus water to leave the state as runoff to rivers or to be stored in lakes subject to loss by evaporation, water is redirected to aquifers to be pumped to the surface in times of need.


Good News for Lake Mead, and Consequently Las Vegas: Federal forecasters now expect the Lake Mead reservoir to avoid its first federal shortage declaration next year, thanks to the boost it should get from what could wind up as the wettest winter on the river’s basin in 20 years. Storms in Utah, Colorado and Wyoming over the past month have added more than 3 million acre-feet to the water supply forecast for the Colorado. That’s a 10-year supply for Nevada, which gets 300,000 acre-feet from the river each year.


There is a rather extensive research project going on at the University of Michigan that is designed to find the most effective ways to convert urine into fertilizer that can be used to help plants grow. Urine is rich is nitrogen, phosphorous, and potassium. The current phase of the project features uses of a special toilet that harvests fertilizer ingredients from human urine.


Although reservoirs are seldom thought of as part of the water infrastructure that needs maintenance, water managers are catching on that many of the nation’s reservoirs are operating at a fraction of their original capacity because they are filling with silt, sand and gravel. Evidence is growing that cleaning the debris out of our reservoirs to restore their holding capacity makes more sense than searching for new sources of water by building dams and drilling more wells.



Gazette’s Famous Water Picture Series: The Lake Berryessa Glory Hole



Lake Berryessa Glory Hole

Lake Berryessa is the largest lake in Napa County, California. The reservoir in the Vaca Mountains is formed by the Monticello Dam, which provides water and hydroelectricity to the North Bay region of the San Francisco Bay Area.

What you see in the picture is the dam’s spillway, which because of California’s drought had not overflowed for a long, long time. After a drought-ridden 10-year period, in February of 2017 water finally spilled into Lake Berryessa’s Glory Hole, bringing an end to the longest gap between spills in the lake’s history.

The Glory Hole is near the dam on the southeast side of the reservoir. It is an open bell-mouth spillway, 72 feet in diameter. The pipe has a straight drop of 200 feet,  and the diameter shrinks down to about 28 feet. The spillway has a maximum capacity of 48,000 cfs (cubic feet per second).  One cubic foot per second is about 450 gallons per minute, so the Glory Hole’s capacity to drain the lake is about 21 million gpm.  The spillway operates when there is excess water in the reservoir. In 2017 after heavy rains it started flowing, for the first time since 2006.

In 1997 a woman was killed after being pulled inside the spillway.


The Glory Hole when it isn’t overflowing


History of Ultraviolet Water Treatment


Although UV has other applications in water treatment, such as chloramine reduction, by far the most common use is for germicidal disinfection. As the picture illustrates, the standard UV dosage for germicidal treatment is 254 nanometers.

Although it’s taken a long time for the technology to become widely adopted, UV has been around for a long time. In 1877, the germicidal properties of sunlight were discovered and it was only a matter of time before people tried to apply this knowledge for practical use. In 1903, Niels Fensen received a Nobel Prize for his use of ultraviolet light to combat tuberculosis, and in 1910, the first drinking water disinfection system opened in Marseilles, France.

From that time, the technology changed very little until the 1930s, when the first tubular lamps were developed. The tubular lamp allowed for easier applications and different configurations for use. In the 1950s, the first truly significant research into UV disinfection began. By the 1960s, UV disinfection was becoming more widely used in commercial applications and was creeping into the residential market.

Today, ultraviolet disinfection is widely accepted as an effective treatment for the removal of microbiological contaminants from water. Although it was initially viewed as a treatment for un-chlorinated well water, the use of UV for city water residential applications is increasing rapidly. As the infrastructure that cities use to deliver water to customers deteriorates, point-of-entry UV is expected to become a standard feature in homes.

Even highly chlorine-resistant microbes such as Giardia and Cryptosporidium can be effectively eliminated from water with UV. UV systems are becoming an increasingly popular alternative to chemical treatment for many applications.

Reference: Viqua.

See also,  The Basics of UV Water Treatment.”

Compact Whole House Cartridge-Style Filter Installation



Compact Whole House Filters Installed in Series.  Water passes through the sediment filter and then through the carbon block filter.

An extremely versatile product,  Pure Water Products’ Compact Whole House Filters can be installed in series, as shown above, or in parallel, as shown in the picture below. (more…)

Backwashing Filters with 4″ Top Holes


Fleck 2850 Filter, 21″ X 62″.  Will support a service flow of up to 50 gallons per minute.

Most residential backwashing filters have 2.5″ threaded top holes in the mineral tank. Conventional “small” filter valves like the Fleck 5600, Fleck 2510, and Fleck 5810 screw into 2.5″ top holes.  These control valves can be used on tanks up to 13″ in diameter.  Beginning with 14″ tanks, most have 4″ top holes and require the use of larger filter valves, like the Fleck 2750, 2850, or 3150.  Tanks with 4″ holes are available up to 24″ X 72″ in size. (The next larger size of tanks have a 6″ flange connection on top rather than a threaded hole.)

For want of better name, we call the filters made with the second size top hole 4″ filters. The filter above is from this group. (more…)

Turning Water Into Electricity

Pure Water Gazette’s Famous Water Picture Series


Jalanica Lake, 2017

A large artificial lake in the Balkan state of Bosnia and Herzegovina, called Jalanica Lake, totally vanished this month and with it an estimated 2 million fish.

Water levels in the lake are usually regulated to keep enough water to generate hydroelectricity and to avoid floods in the city of Mostar, which lies downstream. So it came as a surprise to local people to see the lake completely drained and with it all its life gone.

Normally, the lake is 30 kilometres long, around a kilometre wide with a depth of about 70 metres. Water levels had dramatically dropped twice before, during droughts in 2005 and 2012, but never by this much. (more…)

How Lead Got Into Flint’s Water

The following is excerpted from an excellent article by Michael Torrice  in Chemical & Engineering News. It gives a concise and clear explanation of the procedures that city water departments use to keep contaminants like lead, copper, and iron in the pipes and not in the water, and it shows how fragile this system is and what happens when, through ignorance, greed, or lack of concern, water officials fail to follow the rules.–Hardly Waite.


Lead contamination is the most troubling in a series of water problems that have plagued Flint since the summer of 2014. All of them were caused by corrosion in the lead and iron pipes that distribute water to city residents. When the city began using the Flint River as its water source in April 2014, it didn’t adequately control the water’s ability to corrode those pipes. This led to high lead levels, rust-colored tap water, and possibly the growth of pathogenic microbes.

The pipes in Flint’s old distribution system had seen the same water for decades. Switching water supplies in 2014 changed the chemistry of the water flowing through those pipes. When a switch like this happens, the water system is going to move toward a new equilibrium, says Daniel Giammar, an environmental engineer at Washington University in St. Louis. “It could be catastrophic as it was in Flint, or it could be a small change.”


The Issues with “Softened Water”


 You’ll sing better with softened water (once you realize that the slimy feeling  is really good for you)

As pure water falls to earth, it picks up contaminants, absorbing gases like carbon dioxide and dissolving metals and minerals it comes in contact with. Rain water is naturally “soft,” low in Total Dissolved Solids (TDS),  but it is “aggressive,” looking for minerals to dissolve. As it picks up minerals like calcium and magnesium, it become “hard.”

Even small amounts of hardness minerals, calcium and magnesium,  cause the water to exhibit typical hard-water characteristics. The higher the hardness level, the more evident the problems will be. Residential and commercial water users typically identify two significant problems when dealing with hard water:

Scale: Hardness scale causes water heaters to waste energy and eventually fail,  and unattractive mineral deposits accumulate on fixtures. Faucets and appliances fail. Metal pipes pick up interior scale deposits and inhibit the free flow of water.

Soap interactions: Laundering results aren’t satisfactory; dishes, glasses and silverware are not clean enough and larger amounts of cleaning materials are required. (more…)

How We Can Better Plan Our Cities to Utilize Stormwater

We are finally learning that stormwater can be an asset to communities but now we need to make some urban planning and engineering changes to take advantage of it

by Rinaldo Veseliza


Our urban areas have lost their ability to naturally recycle stormwater due to the impervious nature of infrastructure engineering over the past 100 years. We have been building roadways and streets to capture the runoff and send it somewhere else, usually to the river or ocean. For decades in California, controlling stormwater was the main goal but today, with more water scarcity, we are beginning to see this same water more as an asset and less as a liability. (more…)