dChan
Anonymous ID: 36a2c9 May 24, 2022, 1:34 a.m. No.16331701   🗄️.is 🔗kun   >>1817 >>1979 >>1980 >>2157 >>2203

https://www.motherjones.com/environment/2009/04/sludge-happens/

 

IN AUGUST 1987, the National Park Service tore up the White House’s South Lawn and tilled in heaps of a new, locally produced fertilizer. The weedy plot’s transformation into a carpet of green caught gardeners’ attention, and soon there was a waiting list to buy bags of ComPRO, a compost made from nearby wastewater plants’ solid effluent, a.k.a. sewage sludge. Four years later, dumping sewage into the ocean was banned, and sludge went national. The Environmental Protection Agency launched a PR push to rebrand it as an all-purpose soil conditioner and fertilizer it innocuously called “biosolids.” If sludge was good enough for the first family, the agency reminded us, then surely it was good enough for the rest of America. “The Clintons are walking around on poo,” the EPA’s sludge chief quipped in 1998. “But it’s very clean poo.”

 

Today, more than half the 15 trillion gallons of sewage Americans flush annually is biologically scrubbed, “dewatered,” and processed into products with names like BioEdge, Nitrohumus, and Vital Cycle and spread on farmland, lawns, and home vegetable gardens. (The rest is incinerated or landfilled.) Recycling sewage is big business: In 2007 the Carlyle Group paid $772 million for the sludge-residuals company Synagro, whose products are the most popular on the market. Sludge could be the ultimate growth industry; as one trade publication observes dryly, “There will continue to be more wastewater solids to manage with every passing year.”

 

Today, more than half the 15 trillion gallons of sewage Americans flush annually is biologically scrubbed, “dewatered,” and processed into products with names like BioEdge, Nitrohumus, and Vital Cycle and spread on farmland, lawns, and home vegetable gardens. (The rest is incinerated or landfilled.) Recycling sewage is big business: In 2007 the Carlyle Group paid $772 million for the sludge-residuals company Synagro, whose products are the most popular on the market. Sludge could be the ultimate growth industry; as one trade publication observes dryly, “There will continue to be more wastewater solids to manage with every passing year.”

 

In theory, recycling poop is the perfect solution to the one truly unavoidable byproduct of human civilization. Turning sewage into a potent, inexpensive fertilizer means cleaner rivers and oceans. But as sludge has spread across the country, so have concerns that it may cause as many environmental problems as it solves. In communities where sludge has been used, residents have reported ailments ranging from migraines to pneumonia to mysterious deaths. In a 1994 episode often cited by sludge foes, an 11-year-old Pennsylvania boy died of a staph infection after biking through sludge at an abandoned mine.

Anonymous ID: 36a2c9 May 24, 2022, 2:07 a.m. No.16331784   🗄️.is 🔗kun

MIGHT THERE BE a better way to get rid of sludge? Perhaps, thanks to this nifty fact: A single American’s daily sludge output can generate enough power to light a 60-watt bulb for more than nine hours a day. Sludge is rich in methane, the main component of natural gas. That means that the wastewater sector, which uses about 1 percent of the nation’s electricity, could power itself with sludge and possibly have wattage to spare.

Anonymous ID: 36a2c9 May 24, 2022, 2:11 a.m. No.16331795   🗄️.is 🔗kun   >>1803

So far, however, fewer than 10 percent of the nation’s 6,000 public wastewater plants have anaerobic digesters that can extract methane from sludge; of those, just 20 percent burn the gas for energy. However, other promising projects are under way. Flint, Michigan, is one of several cities worldwide to fuel buses with gas from sludge. Last summer, Los Angeles began injecting sludge into a mile-deep well, where pressure and heat are expected to release enough methane to power 1,000 homes.

 

Sludge power is only a partial solution. At best, methane removal cuts sludge’s volume in half. Currently, leftover sludge is often incinerated, releasing heavy metals into the air and packing landfills with enough ash each year to fill more than 3,100 dump trucks. New high-efficiency poop-to-power plants can minimize those impacts. Using high-temperature or low-oxygen reactions, they covert sludge into a synthetic gas or oil, or a char similar to barbecue briquettes. The process can produce twice as much energy as it consumes, says Brian Dooley, a spokesman for Atlanta-based EnerTech, which built the first commercial plant of its kind in Southern California last year. The plant converts sludge from about a third of Los Angeles and Orange counties into a char that replaces coal at a local cement kiln; its ash is mixed into the cement. Such efforts, which reduce landfilling and emissions, have earned praise from some anti-sludge groups. Caroline Snyder, the founder of Citizens for Sludge-Free Land, calls it a “win-win situation.”

 

The EPA says sludge power holds promise, but it’s not quite ready to quit pushing sludge as a wonder fertilizer. This hasn’t deterred the sewage industry, which sees a chance to get into the renewable energy business and put a stop to the stream of health complaints and costly lawsuits. “After almost 40 years of working in biosolids,” a WERF official wrote in a recent newsletter, “I never thought I’d say this: it is an exciting time for sludge!”