Serenity: A Brief History of Toilets (and Toilet Water)
Robert E. Mace, Ph.D., P.G.The Meadows Center for Water & the Environment
Texas State Universitypresented to
16TH Annual CASE ConferenceCapital Area Suburban Exchange
South Padre, TexasJune 22, 2019
Why did I eat lunch at Taco Bell today?
Will they miss me if I’m gone for the
next 45 minutes?
•Stone Age toilets• 3100-2500 BC at Skara Brae• Orkney Islands, Scotland
photo from Toilet-guru.com
• Indus Valley• Between India and Pakistan• First known urban sanitation
system• Houses had their own toilets• Central collection via flowing
water• Almost every house had a
toilet• ~2800 BC
•~1700 BC• Egypt• Crete (Minoans)• Persia
Egyptian toilet
Crete sewer system
example from Ostia Antica
•Roman• 500 to 0 BC• Cloacina, Venus of the Sewer
•Medieval toilet
• Modern toilets• 1596: Sir John Harington
invented a flushing toilet called the Ajax
• 1775: Alexander Cumming was granted a patent for a flushing toilet with S-trap
• 1778: Joseph Bramah improved the design
• ~1880: Thomas Crapper advocated for sanitary ware; improved the S-trap
modern toilets
• Older toilets use up to 7 gallons per flush
• Federal plumbing standards require no more than 1.6 gallons per flush (gpf)
• High-efficiency single-flush toilets are 1.28 gpf
• Our toilets are 1.1 gpf
Different flavors of reuse• de facto reuse
• unplanned reuse• Indirect reuse
• planned reuse with an environmental buffer• Direct reuse
• planned reuse without an environmental buffer • “pipe to pipe”
• Sub-flavors of reuse• potable• nonpotable
de facto reuse in the
Trinity River
from NRC (2012)
Lake Livingston
• 500 million gallons per day of treated wastewaterfrom DFW Metroplex
• effluent-dominated river• 50% of normal flow• 80% in times of drought
• primary source of water (66% of supplies) for Houston
El Paso Water UtilitiesHueco Bolson Recharge ProjectIndirect Reusesince 1985
Effluent Line
Injection Wells
Production Wells
Fred Hervey Water
Reclamation Plant
Power Plant
Richland-Chambers Engineered WetlandTarrant Regional Water Districtindirect reuse
First of its kind in the United States
image from NTMWSD
Water Supply ImpactLake Lavon Yield:104,000 ac-ft/yr(93 MGD)
East Fork Water Supply Project:102,000 ac-ft/yr(91 MGD)
+
Total Yield: 206,000 ac-ft/yr(184 MGD)
+
image from NTMWSD
Direct reuse in San Antonio
Raw Water Production Facility, Big Spring, Texas
John Grant, Colorado River Municipal Water District
photo by Torin Halsey, Time Record News
“I guess that means I get to drink my beer twice…”
Daniel Nix, City of Wichita Falls, partaking of the water from the reuse project
photo by Torin Halsey, Times Record News
images from Daily WOD Wear
Micro/emerging contaminantspathogens (adenovirus, norovirus, salmonella, cryptosporidium)
Where’smy
water?
reuse in the water plan
from the 2017 State Water Plan
“Don’t drink downstream of the herd.”
• Direct non-potable• 12,000 AFY by 2040• 90,000 AFY by 2115
• Indirect potable reuse through Lady Bird Lake• 11,000 AFR by 2040• 20,000 AFY by 2115
• Distributed wastewater reuse• 3,154 AFY by 2040• 30,049 AFY by 2115
• Sewer Mining• 1,000 AFY by 2040• 5,284 AFY by 2115
• Building-scale wastewater reuse• 1,323 AFY by 2040• 7,875 AFY by 2115
• Greywater harvesting• 2,126 AFY by 2040• 12,667 AFY by 2115
AFY = acre-feet per year
Looks like I get to drink my beer
twice…
That’s more than I ever wanted to
know about toilets…
