Last week, after Hill Country floodwaters overwhelmed Austin's water treatment plants, the city warned residents to boil their tap water first before drinking it. We were interviewed about the advisory by a couple of media outlets, and we noted that while this was apparently the first "boil water" notice in Austin's history, these notices are common in Texas, and that there's at least one warning every month. It turns out that we were off — way off.
According to a new study published in the September issue of the Texas Water Journal, around 1,000 boil water notices are issued in Texas every year. The study also found that from January 2011 to December 2016, the number of boil water notices (BWNs) increased by 73%. The number of sanitary sewer overflows (SSOs) increased by 983%, and the number of lead contamination public education (LCPE) events increased by 1,300%. The report states that "the reasons for the trends are most likely due to pressure on aging water infrastructure from rapid population increases and increased frequency of extreme weather events,. e.g. flooding and hurricanes."
Boil Water Notices (BWNs)
"The overall increase—from 544 incidents reported in 2011 to 939 by the end of 2016—represents a 73% increase in the number of BWNs reported in Texas. Four regions—G, H, I, and K—recorded a higher than average number of incidents. Regions G, H, I, and K are also high population centers, representing approximately 42% of the total Texas population. A notable spike can be seen between 2011 and 2012 where incidents increased by 82% from 544 to 990, respectively. The spike is most likely attributed to the regional impacts noted from the severe drought that began in 2009 and peaked in 2011. Severe droughts and resulting soil moisture loss can damage infrastructure, resulting in line leaks, water main breaks, and overall system pressure loss."
Sanitary Sewer Overflows (SSOs)
"In the six-year period examined, there were 7,982 SSO incidents; the total rose by 983% over this period with approximately 424 incidents in 2011 and 4,594 in 2016 across all 16 regions. Regions H and L recorded the highest total number of SSOs at 2,468 and 1,916, respectively. Both Region H and L include segments of the Gulf Coast, making them more susceptible to extreme wet weather conditions, often causing flooding. Floods can overwhelm aging wastewater systems and result in SSOs.
"There were two notable spikes observed in the SSO data. The first spike occurred between 2014 and 2015, during which the number of reported statewide SSO incidents increased by 79%, which was likely caused by the heavy rainfall and resulting flooding at the end of the 2010–2014 Texas drought. The second spike was specific to Region H, where the number of SSOs rose from 75 in 2015 to 2,364 in 2016. This spike was driven mainly by Region H and the history of SSO incidents and response to the same by the Greater Houston area in particular.
"The Houston region is known for subsidence issues. Periods of drought followed by flooding can cause significant soil movement, particularly in clay soil areas. This movement can wreak havoc on infrastructure and cause flooding events that increase infiltration to sewer systems, which can then quickly overtake their design capacity, resulting in SSOs."
Lead Contamination Public Education (LCPE)
"There was an overall increase in the number of LCPEs recorded, totaling 226 incidents. There was a notable spike between 2012 and 2013 where reported incidents increased by 1,100% from 4 to 48, respectively. This was most likely attributed to better reporting from the jurisdictions to TCEQ. In Region H, where the highest number of incidents was recorded, this trend was most likely due to the influence from the petrochemical industry. Aging or poorly maintained infrastructure also contributed to the trend.
"Unsurprisingly, the number of LCPE notices is relatively low. Lead contamination in drinking water supply is not common in the United States. However, the water crisis in Flint, Michigan, heightened public fears on the issue, especially because of the amplified risks to infants and children. With the EPA declaring that no level of lead is safe for children, the authors believe city and utility leaders have to make a greater investment in identifying the lead lines in their jurisdictions and replacing them in order to avoid another crisis similar to Flint."