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Plant & Facilities Engineering

The Plant & Facilities Engineering Blog is the place for conversation and discussion about mechanical and electrical systems, automation and instrumentation, maintenance and management, and products & services as they relate to plant and facilities operation. Here, you'll find everything from application ideas, to news and industry trends, to hot topics and cutting edge innovations.

Kia Enters Indian Market with $1.1 Billion Car Plant

Posted May 14, 2017 12:00 AM by Engineering360 eNewsletter

The South Korean automaker says it plans to produce a compact sedan and compact SUV especially for the Indian market at this new plant. When production begins in the second half of 2019, the plant will produce up to 300,000 units a year.

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'Toilet-to-Tap' Water is Becoming Commonplace

Posted April 06, 2017 9:48 AM by HUSH

I like beer. Do you like beer?

What I like even more than beer is enjoying beer, which to me is an altogether different matter. This means summer evenings at the farm brewery. Seeking out new craft brands and bottles. Maintaining a modest homebrewing hobby. All while trying to be as non-judgmental as possible toward macrobrews.

Yet I might’ve avoided the limited run batch of Stone Brewing’s Full Circle Pale Ale had I the chance to try it. And that’s because this beer was brewed using recycled water.

Stone Brewing, based in San Diego, brewed Full Circle to highlight the city’s new water program called Pure Water. It is a pilot initiative that currently purifies one million of the 30 million gallons of wastewater San Diego produces each day. The hope is that eventually one-third of San Diego’s potable water supply will come from purified wastewater. It would be invaluable for a city that imports 90% of its tap water, due to droughts and an unwillingness to build desalination plants.

Reusing greywater and blackwater for a second time is not a new idea. Greywater is commonly reused for things like industrial washing or process water. Even blackwater has value in irrigation. But the idea of recycling toilet water for use as drinking water is, frankly, gross. And the fact that water recycling is sometimes called “toilet-to-tap” isn’t exactly a great marketing strategy.

You might be relieved to learn that only the idea of recycled water is gross. Stone Brewing actually had to add minerals back into the water they received from the Pure Water program, as it was too clean. The brewery had been using tap water with a total dissolved solids count of 300-600 parts per million. The purified wastewater had less than 100 ppm, so solids were added to the water to make it more like tap water.

Limited research indicates (.pdf) that recycled wastewater (water that has been through at least three stages of disinfection and purification) tends to have fewer contaminants than drinking water that has been through two stages of processing, the minimum according to U.S. law. The aversion to reusing wastewater as drinking water is almost purely psychological. Thirteen percent of people said they would never drink recycled water, even after learning about purification and sustainability.

Want more [anecdotal] proof? Watch Bill Gates challenge Jimmy Fallon to tell the difference between recycled water and bottled water.

Like it or not, wastewater reuse has been occurring in some locations for thousands of years. Often, a wastewater treatment plant discharges into a water source that is used as drinking water for another town downstream. The Hudson, Mississippi and Thames rivers are all examples of this, which is called indirect potable reuse. By the time a water molecule has reached New Orleans’ via the Mississippi, scientists estimate that five animals had previously consumed and urinated that molecule.

However, the city of San Diego has not begun pumping recycled water back in to the drinking supply, at least not yet. That doesn’t mean other cities aren’t considering it. After failed attempts at cloud seeding and evaporation repression, the city of Wichita Falls, Texas, has been delivering ultra-clean recycled wastewater to residents’ taps since 2014. Other drought-stricken cities in Texas and New Mexico have followed suit, and there is a proposal to do the same in Los Angeles.

Residents who squirm at the idea of drinking recycled water might want to consider moving—or at least buying a Brita filter.

29 comments; last comment on 04/08/2017
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New Troubles Hit Kemper County Clean Coal Plant

Posted April 05, 2017 12:00 AM by Engineering360 eNewsletter

The Kemper County integrated gasification combined cycle (IGCC) power plant will miss its planned mid-March in-service date. Mississippi Power said tube leaks hit one of the plant's synthetic gas coolers. Engineers started an outage to make repairs, forcing another delay in commissioning the IGCC.

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Will It or Won't It? The Oroville Dam's Potential Collapse

Posted February 16, 2017 10:25 AM by HUSH
Pathfinder Tags: dam infrastructure Oroville weather

It isn’t too hard to argue that here in the United States we take our infrastructure for granted. Next month, the American Society of Civil Engineers will release its 2017 report card on the state of American infrastructure. ASCE updates the report card every four years. In 2013, the cumulative GPA for the U.S. was a D+, up from a D in 2009. No one is expecting the U.S. to make Honor Roll this year.

One of the lowlights from 2013 was the country’s grades on dams, also a D. It noted that the average age of the 84,000 dams in the U.S. was 52 years old. The number of high-hazard dams—those whose failure may cause loss of life—has steadily risen over the years, all the way up to 14,000. The reasons for this are twofold. Dam construction techniques have improved and old dams just don’t stack up to new evaluations. Also, more people have moved into the low-lying areas that are shielded by dam walls, some of which were built to poorer standards as formerly the area was undeveloped and less important.

Today, one of the most pressing U.S. infrastructure challenges in recent memory continues and the threat of a partial dam collapse persists even as workers attempt to reinforce the dam at this very moment.

After days of rain, on February 7 Oroville Dam officials opened the dam’s spillway so excess water could begin to drain from Lake Oroville, which is at its highest February water level in more than 30 years. The spillway routes water past the dam’s hydroelectric plant as well as bypass valves that had been broken since 2009.

Despite the flushing being well within the spillway’s design limits, operators noticed a hole developing in the spillway. With the lake’s water level rising up to 20 feet per day the spillway had to continue to be used, and gradually the hole grew into a crater. Eventually the debris carried from the 500 ft. x 300 ft. by 50 ft. crater fell into the river below, blocking the outlet of the hydroelectric plant.

State engineers determined that they would need to use the dam’s last resort, its emergency spillway. While it’s not made of concrete like the main spillway, the emergency spillway is a nearby embankment that sits 20 ft. lower than the lip of the dam. On February 11, water crested the edge of the auxiliary spillway. Slowly but surely the water eroded this hillside too, and finally on February 12 an evacuation order was given to 188,000 residents of the Feather River valley. Engineers became less confident in the spillway’s ability to hold as snowpack that is 50% above normal combined with excessive rain. With more rain in the forecast for this week, there is no shortage of wet stuff.

It’s arguable that this disaster-in-the-making could have been prevented. It is well-known that California is in the midst of an epic seesaw drought. Perhaps that is why in 2005, state and federal officials decided not to reinforce the emergency spillway, despite requests from environmental groups including the Sierra Club. What’s notable is that the auxiliary spillway began to erode with water flows of 12,600 ft.³/s, a volume much lower than its specified capacity of 350,000 ft.³/s.

Water flow has finally receded to the point where crews are airlifting and excavating boulders and sandbags into place in the gulley of the auxiliary spillway.

As of Valentine’s Day evening, locals were allowed to return home but were prompted to remain ready for another potential evacuation. The situation at Lake Oroville is tenuous, but appears to be in control for now. The same cannot be said for thousands of other risky dams around the country.

17 comments; last comment on 02/21/2017
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3D Scanning Speeds Assembly Line Changeovers

Posted February 04, 2017 12:00 AM by Engineering360 eNewsletter

A novel application of 3D scanner technology could help to speed retooling of automotive assembly lines. Researchers at Würzburg University are collaborating with a team at Volkswagen AG to streamline changeovers from one model to another.

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