NEED Visits Blue Plains

This is just a guess. But Blue Plains Advanced Wastewater Treatment Plant has probably never given a tour of their facility with quite as many questions about their statistics as they had Thursday, when NEED brought in a bus full of curious employees from the U.S. Energy Information Administration.
Bill Brower, Program Manager for Biosolid Operations, stepped in as the knowledgeable tour guide, directing the bus through the grounds, herding everyone out for brief, chilly stops at different stations along their 150 acres on the bank of the Potomac River.
As the largest advanced wastewater treatment facility in the world and the biggest single-source user of energy in the D.C. area, there was much that intrigued the motley EIA staff of statisticians, analysts, and economists.
“How far are you from total capacity?”
“When do you foresee being energy neutral?”
“What’s the average time water spends in these tanks?”
Bill gave every question a thorough answer—even the tougher, more ethical questions like, “So, you give your biosolids to local farmers as compost for free? Since it’s valuable to them, why aren’t you charging for it?”
The tour group was inquisitive and thoughtful as they were guided through the chronological course that wastewater (and its subsequent sludge) takes through the plant.
At one particularly fragrant portion of the tour, Bill guided 15 hard-hat-covered heads into one of wastewater’s initial stops, opening a latch to reveal what looked like a formidable, mechanical comb. As the group watched it rake decomposing trash, personal hygiene materials, and dripping, browned paper towels from the wastewater, one person commented, “I bet nobody feels like eating much around here.”
Next stop: the holding tanks. Here, water gets a break. The purpose is to twofold: allow the stirred up debris and particles to settle to the bottom, where they can be removed, and allow the oil and fats from within the water to rise to the top to be skimmed off. (This same oil is used at a later point as fuel for the plant.)
Next, suspended matter too stubborn to sink to the bottom of the holding tanks is removed from the water using a specific cocktail of microorganisms. Big fans pump air into the water, giving the microorganisms enough oxygen to function as they feast. This step, Bill noted to the energy enthusiasts, used a large portion of their energy demands.
Afterwards, the water at this particular plant goes through a tertiary treatment of nitrogen removal—a step that qualifies Blue Plains as an advanced plant. Bill pointed out that the fragile ecosystem of the Potomac, where the water is dumped, is always the primary concern.
Now separated out, the biosludge goes through an advanced system of digestion under extreme pressure and heat. The end product? A grade A sludge that they later mix with an equal amount of wood chips—ta da! Compost! The farmers love it, we’re told. Bill even uses it in his garden. The tour group, skeptical at first, took a sniff of the compost one by one.
“Doesn’t even smell bad!” they noted, surprised.
A few hours later, newly enlightened and statistically satisfied, the group thanked Bill for his insightful tour and, despite all they’d seen drudged out of murky water, still found room for a tasty lunch at the National Harbor.