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Chuck Haas

@chuckhaas.bsky.social
360 followers 191 following 88 posts

Professor of Environmental Engineeering at Drexel University. Water treatment & reuse, risk assessment (especially microbiological risk) & environmental health. Member, National Academy of Engineering #Philadelphia also @ProfCharlesHaas@mastodon.social

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Chuck Haas @chuckhaas.bsky.social · 28/09/2026
Good Engineering for Bad Purposes. A musing on #engineeringethics chaasblog.wordpress.com/2026/09/28/1...
chaasblog.wordpress.com
Good Engineering for Bad Purposes
1. A ventilation problem Suppose you are handed the following problem. A sealed room of known volume contains a toxic gas at a known concentration. The client wants the room cleared to a safe level…
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Chuck Haas @chuckhaas.bsky.social · 19/09/2026
en.wikipedia.org/wiki/Wetwork
en.wikipedia.org
Wetwork - Wikipedia
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Chuck Haas @chuckhaas.bsky.social · 19/09/2026
by any chance are you using safari on mac with a hide my ip - if so, you need to disable it to use google scholar
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Chuck Haas @chuckhaas.bsky.social · 08/09/2026
What most environmental engineers had a strong strong sense of at the time.
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Faye McNeill @vfmcneill.bsky.social · 08/09/2026
www.nytimes.com/2026/09/07/n...
nytimes.com
After 9/11, Documents Suggest New Yorkers Were Misled About Air Quality
The Mamdani administration is releasing more than 170,000 pages of documents related to the air quality around the World Trade Center site in the months after the Sept. 11 attacks.
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Chuck Haas @chuckhaas.bsky.social · 28/08/2026
History doesn't repeat itself, but it rhymes. en.wikipedia.org/wiki/Ohio_(C...
en.wikipedia.org
Ohio (Crosby, Stills, Nash & Young song) - Wikipedia
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Chuck Haas @chuckhaas.bsky.social · 24/08/2026
Don't they believe that it only took 40 days and 40 nights to cause the great flood - so biblical "evidence" exists.
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Chuck Haas @chuckhaas.bsky.social · 24/08/2026
New blog post: "Co-creation: The Next Rung Not a Different Ladder" Is the use of LLM really programming? And what do we do? An engineering perspective. #AI #Programming chaasblog.wordpress.com/2026/08/24/c...
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Chuck Haas @chuckhaas.bsky.social · 22/08/2026
Philadelphian: What youse gonna do about it?
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Chuck Haas @chuckhaas.bsky.social · 14/08/2026
My new book "Environmental Engineering for Pathogen Control" launches Aug 2026. 560 pages of NAE-level insights on air, water, and soil. Pre-order via Amazon: www.amazon.com/Environmenta... #QMRA #PublicHealth #EnvironmentalEngineering @wiley.com
amazon.com
Environmental Engineering for Pathogen Control
Environmental Engineering for Pathogen Control [Haas, Charles N.] on Amazon.com. *FREE* shipping on qualifying offers. Environmental Engineering for Pathogen Control
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Chuck Haas @chuckhaas.bsky.social · 13/08/2026
✅
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Chuck Haas @chuckhaas.bsky.social · 13/08/2026
tell me more. though I am making good use of AI (more Claude)
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Chuck Haas @chuckhaas.bsky.social · 11/08/2026
Epistemic trespass and Research parasites Thoughts in a new blog piece #epistemictrespass #researchparasites #interdisciplinarity chaasblog.wordpress.com/2026/08/11/i...
chaasblog.wordpress.com
In Praise of Epistemic Trespassers and Research Parasites
1. The weed in the field A farmer walks his carefully cultivated field and notices an unfamiliar plant among the crop. He recognizes a weed — an invader competing for nutrients, water, and light. H…
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Chuck Haas @chuckhaas.bsky.social · 08/08/2026
I was a student during the waning days of Retalliata, was a faculty member during the Tom Martin -> Lou Collens era. I thought Retalliata was bad; Martin at the end was worse, but this takes the cake. 😥😡
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Chuck Haas @chuckhaas.bsky.social · 03/08/2026
Academic Writing - workflow in the age of #AI Some thoughts on my recent personal experience chaasblog.wordpress.com/2026/08/03/a...
chaasblog.wordpress.com
Academic Writing Workflow in the Age of AI
Like many academics who have been active for some time, I have a pool of gestating ideas and prior data sets that have never been published. There was a barrier, call it an "activation energy,…
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David S. Cohen @dsc250.bsky.social · 26/07/2026
I was biking today just south of the Delaware Water Gap on the PA side and amidst the beautiful roads and farms it seemed EVERYONE had anti data center signs on their property.
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Chuck Haas @chuckhaas.bsky.social · 26/07/2026
our farmers market has reliably had romaine for weeks.
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Chaucer Doth Tweet @levostregc.bsky.social · 25/07/2026
Academic organizations hadde bettir actuallye be brave and protecte each othir or else the last one ther will have no taske besydes turninge out the lightes and leavinge the key yn the envelope for big businesse.
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PNAS Nexus @pnasnexus.org · 25/07/2026
The cost of launching a kilogram of cargo into orbit fell from $87,023 in 1960 to $3,868 in 2025. For each doubling of cumulative payload, the average cost to launch a kg has decreased by 21.2%, positioning it to reach $300 per kg by 2040. In PNAS Nexus: ow.ly/n7Kh50ZsqvA
Starship at Starbase in Boca Chica, Texas, June 30, 2022.
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Chuck Haas @chuckhaas.bsky.social · 22/07/2026
Can Close-by Cooling Towers be "Contagious" for #Legionella. The current NYC outbreak has had me thinking about this issue. A blog piece (aided by #Claude). chaasblog.wordpress.com/2026/07/22/c...
chaasblog.wordpress.com
Can Closely Situated Cooling Towers be “Contagious” For Legionella?
The present Legionella outbreak in New York City, and past outbreaks in dense urban areas, have had me started to think about whether multiple cooling towers in such areas may interact. If Legionel…
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Peter Gleick @petergleick.bsky.social · 19/07/2026
People have been asking me this question for decades. The answer is in most places, reducing demand by improving efficiency and cutting waste, and recycling and reusing wastewater, are cheaper, easier, and more environmentally beneficial than desalination. www.bostonglobe.com/2026/07/19/o...
bostonglobe.com
The world needs more fresh water. Why isn’t desalination the answer? - The Boston Globe
There is obvious demand for the technology. And solar power should be making it more economical. If only it were that simple.
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Peter Tarras @petertarras.bsky.social · 08/07/2026
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Gigi Gronvall @ggronvall.bsky.social · 06/07/2026
open.substack.com/pub/holdenth...
open.substack.com
Red alert: The OMB regulations could disable science permanently
All hands report to stations
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Chuck Haas @chuckhaas.bsky.social · 01/07/2026
A shame not to have any meet and greet at AWWA
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Chuck Haas @chuckhaas.bsky.social · 26/06/2026
wait till they pull out "nattering nabobs of negativism"
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PNAS Nexus @pnasnexus.org · 22/06/2026
A model of influenza outbreaks reveals a U-shaped relationship with specific humidity. Very humid and very dry conditions can both favor influenza. The model can predict outbreaks in temperate and tropical climates. In PNAS Nexus: ow.ly/SYuX50ZflN5
Predicted average daily basic reproduction number (R0) based on climate from best fit parameters for each location (vertically scaled).
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PNAS Nexus @pnasnexus.org · 20/06/2026
Considering PNAS Nexus for your next publication? Hear directly from members of the Editorial Board about what makes the journal unique and why interdisciplinary research thrives in PNAS Nexus: ow.ly/oTLL50ZcVEu Submit your manuscript: ow.ly/6YEV50ZcVEv
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Chuck Haas @chuckhaas.bsky.social · 18/06/2026
Re-uping my blog post of yesterday - "Reflections on the Reflecting Pool" chaasblog.wordpress.com/2026/06/17/r...
chaasblog.wordpress.com
Reflections on the Reflecting Pool
As I write this, after another probably tens of millions of dollars spent on the Washington DC reflecting pool to try to deal with what seems to have been a chronic water quality problem (seemingly…
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Chuck Haas @chuckhaas.bsky.social · 18/06/2026
Going back to my blog. Posted "Reflections on the Reflecting Pool". They need and #environmentalengineering mindset to solve this. #ReflectingPool chaasblog.wordpress.com/2026/06/17/r...
chaasblog.wordpress.com
Charles Haas' Blog
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Chuck Haas @chuckhaas.bsky.social · 16/06/2026
Moving your office will cure you of that habit. I junked several file drawers of my and other reprints - have them as pdfs now
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Chuck Haas @chuckhaas.bsky.social · 31/05/2026
Seven "Dirty" Words in Higher Ed. - 7. #Assessment open.substack.com/pub/professo... #highereducation
open.substack.com
Seven "Dirty" Words in Higher Ed. - 7. Assessment
We have arrived at the last of the seven words in this series, and in some ways, it is the most paradoxical.
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Nigel Goldenfeld @nigelgoldenfeld.bsky.social · 30/05/2026
Proposed regulations from Office of the Management of the Budget will be devastating for science. Fight back by getting informed and writing personalized comments in the Federal Register comment period. Excellent resources from @standupforscience.net fight2win.standupforscience.net
fight2win.standupforscience.net
Stand up for Science
Stand up for Science
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Saganism @sagan.bsky.social · 23/05/2026
“Cutting off fundamental, curiosity-driven science is like eating the seed corn. We may have a little more to eat next winter but what will we plant so we and our children will have enough to get through the winters to come?” ― Carl Sagan
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Costa Samaras @costasamaras.com · 19/05/2026
These folks just published a real study measuring the local temp impacts of data centers: about +1.8°F (max 4°F) in neighborhoods up to a third of a mile nearby. Much smaller than the other draft paper, but in neighborhoods, need to mitigate waste heat. asmedigitalcollection.asme.org/sustainableb...
asmedigitalcollection.asme.org
Data Center Waste Heat as an Emerging Urban Thermal Hazard: First Field Measurements of Neighborhood-Scale Air Temperature Impacts
Abstract. Data centers are among the fastest-growing sources of concentrated anthropogenic heat in urban environments. Despite heat flux densities that exceed peak solar irradiance by a factor of 2–6,...
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Proceedings of the National Academy of Sciences @pnas.org · 09/05/2026
Why publish with PNAS & PNAS Nexus ✅ Prestigious journals ✅ Rigorous peer review ✅ Open #access options ✅ Global #visibility & #impact Share your research with a global #scientific audience. Submit today: PNAS: ow.ly/Hw5k50YX09V PNAS Nexus: ow.ly/FeY650YX07c
Elevate your impact and amplify your research with PNAS and PNAS Nexus. Submit your manuscript today!
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Chuck Haas @chuckhaas.bsky.social · 11/05/2026
This is really starting to put a lie to the idea that close direct contact is needed. There is almost certainly some portion of infector -> environment -> receptor pathway
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Chuck Haas @chuckhaas.bsky.social · 11/05/2026
I fully agree that the quick dismissal of person to person transmission of #hantavirus is ill-founded. Have been reading a number of papers. This one (animal model) is particularly enlightening
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Chuck Haas @chuckhaas.bsky.social · 05/05/2026
Seven "Dirty" Words in Higher Ed. - 6. Content open.substack.com/pub/professo... #highereducation
open.substack.com
Seven "Dirty" Words in Higher Ed. - 6. Content
“Content” may be the most quietly corrosive word in this series.
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Chuck Haas @chuckhaas.bsky.social · 06/04/2026
Who did the drafters of the 25th Amendment think the Cabinet would be when they wrote this?
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Chuck Haas @chuckhaas.bsky.social · 31/03/2026
Seven "Dirty" Words in Higher Ed. - 4. Entrepreneurial open.substack.com/pub/professo...
open.substack.com
Seven "Dirty" Words in Higher Ed. - 4. Entrepreneurial
Of all the words in this series, “entrepreneurial” may be the hardest to argue against.
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Chuck Haas @chuckhaas.bsky.social · 19/03/2026
Seven "Dirty" Words in Higher Ed. - 3. The University is a Business open.substack.com/pub/professo...
open.substack.com
Seven "Dirty" Words in Higher Ed. - 3. The University is a Business
Of all the phrases I plan to examine in this series, “the university is a business” is the most foundational.
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Trish Greenhalgh @trishgreenhalgh.bsky.social · 21/02/2026
American professors, who wants to come to Oxford for a year or two? Get in quick - deadline soon. www.balliol.ox.ac.uk/vacancy-geor...
balliol.ox.ac.uk
Vacancy - George Eastman Visiting Professorship
Vacancy - George Eastman Visiting Professorship The University invites expressions of interest in the George Eastman Visiting Professorship for the academic years 2026/2027 and 2027/2028, in an area
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Chuck Haas @chuckhaas.bsky.social · 29/12/2025
Thoughts on #AI , #engineering, and #engineering education in my new blog post. Are we going through stages of grief? chaasblog.wordpress.com/2025/12/29/a...
chaasblog.wordpress.com
AI in Academia and the Five Stages of Grief
The emergence of generative AI has prompted a wide range of reactions across academia—many of them charged, inconsistent, and often deeply personal. While these responses are frequently framed as f…
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Chuck Haas @chuckhaas.bsky.social · 04/12/2025
Oh, when will they ever learn? Oh, when will they ever learn?
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𝙲𝚑𝚊𝚛𝚕𝚎𝚜 𝙲. 𝙼𝚊𝚗𝚗 @charlescmann.bsky.social · 25/11/2025
In 1924, Calvin Coolidge's 16-yr-old son played tennis on the White House grounds w/o wearing socks. He got a blister and was dead from infection a week later. This is unthinkable today—which is why I wrote this series. Cuz the systems that save us from this kind of fate are in urgent need of care.
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Robert Reich @rbreich.bsky.social · 21/10/2025
Amazon controls over a third of the global cloud computing market. Its customers include Capital One, United Airlines, and the US Army. Today's outage should be a wakeup call: Dependence on a handful of powerful corporations is a threat to economic and national security.
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Angie Rasmussen @angierasmussen.bsky.social · 11/10/2025
I don’t know who needs to hear this but the CDC is being eviscerated right now. America is not going to have any kind of outbreak response capacity after tonight. Americans’ health data is no longer secure. Say goodbye to federal public health in any capacity. It’s a disaster. We won’t recover.
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Gregg Gonsalves @gregggonsalves.bsky.social · 11/10/2025
This is beyond bad. All of our disease defenses are down now. We are sitting ducks. This is #RussellVought #DonaldTrump. They are endangering American lives with their insane crusade. These men are hazardous to your health and dangerous to the republic.
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Lissa Harris 🌈🗑️🔥⚔️🐀 @lissaharris.bsky.social · 30/09/2025
they are destroying US climate science on purpose, and it hurts my heart. but take it from an MIT-trained nerdass: all most of us need to know is that we have to stop burning stuff stop burning stuff for heat stop burning stuff for make car go stop burning stuff for power we have the tools
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Kai Kupferschmidt @kakape.bsky.social · 08/09/2025
“We will never know what diseases might have been cured or what advances in technology might have been invented had the lights not gone out in the labs.” 🧪 #giftarticle
nytimes.com
Opinion | We Are Watching a Scientific Superpower Destroy Itself
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