Our air quality improves, but a sewage solution remains elusive
Southwestern Pennsylvania has quietly reached an environmental milestone. After exceeding the Clean Air Act pollution limit for nearly four decades, levels of unhealthy microscopic particles in the sky above the region have fallen to within federal air quality standards for the first time.
Even the region’s hottest air pollution hot spot – the handful of Allegheny County communities immediately downwind of US Steel’s Clairton coke works – met federal standards for the largely invisible particles known as PM2.5 in 2011, according to the latest monitoring data available. “The air is the cleanest it’s been since the Industrial Revolution in terms of fine particulates,” said Jim Thompson, manager of the Allegheny County Health Department’s Air Quality Program.
Meanwhile, a plan to solve another pressing environmental problem – chronic sewage overflows into streams and rivers – was considered too expensive for rate payers in 2012, prompting the Allegheny County Sanitation Authority to come up with a less ambitious approach.
Clearing the air
Finally complying with federal fine particulate air pollution standards is one thing. Staying in compliance is another. In that regard, the region is expected to get help from the federal Cross-State Air Pollution Rule, if and when it is fully implemented. The rule, which is stranded in a federal appellate court, requires steep reductions in sulfur dioxide and nitrogen oxide emissions from coal-fired power plants.
In fact, the region is already feeling the impact, Thompson said. Stricter limits on the chemical compounds were first proposed five years ago. Some electric power utilities, realizing reductions would eventually be enacted, have already installed scrubbers or taken other steps to reduce plant emissions.
An estimated 70 percent of the fine particulate pollution measured in southwestern Pennsylvania is emitted from downwind sources beyond its borders, particularly power plants in the Midwest.
While a reduction in PM2.5 from out-of-state sources is one of the reasons the region’s annual pollution readings dipped below the 15 micrograms per cubic meter federal limit, recent local developments also contributed. Among them was the closing of three aged coke oven batteries at the Clairton works, which were replaced with a new, low-emissions battery that went online in late 2012. And construction of two low-emission quench towers at the plant should be completed this year.
Federal air quality standards tend to be moving targets that are adjusted as more is learned about the health affects of pollutants. PM2.5 limits are no exception. The U.S. Environment Protection Agency is expected to soon consider lowering the annual standard that the region only recently managed to meet.
The region faces a similar challenge meeting standards for ozone, also known as smog, which forms when sunlight reacts with exhaust from cars, trucks, buses and other fossil fuel-burning sources.
Allegheny County finally managed to meet 1997 federal ozone standards in 2011. But it remained in violation of the more stringent 2008 limits of 75 parts per million.
And the latest standard is expected to be revisited in 2013 with an eye toward ratcheting it down to between 60 and 80 parts per million, as recommended by EPA science advisors based on an assessment of health impacts. Short-term ozone exposure can trigger asthma attacks, while long-term exposure can lead to reduced lung function, pulmonary congestion and heart disease.
As with fine particulates, implementation of the Cross-State Air Pollution Rule is expected to help lower ozone in the region by greatly reducing levels of nitrogen oxide, a key component of smog. Such help can’t come too soon. Preliminary data suggest ozone levels increased in Allegheny County in 2012, which was a hot, dry year, particularly in the Midwest, where a significant amount of the region’s ozone originates. “It’s a tough nut to crack,” said Thompson.
A resource at risk
Abundant annual rainfall leaves southwestern Pennsylvania in a fortunate position as much of the world grapples with the prospect of a shortage of fresh water. The region’s challenge is not the availability of water, but effective stewardship to protect the quality of its rivers and streams – something that new Pittsburgh Today water quality maps suggest has not been its strong suit.
Pennsylvania has more impaired waterways than any other state in the nation and the maps show that thousands of miles of them are in southwestern Pennsylvania. Allegheny County is crowded with streams and rivers that fail to meet federal Clean Water Act standards for reasons ranging from acid mine drainage and urban runoff to industrial and wastewater effluent. Dense pockets of non-attaining streams are also found in more rural parts of the region, such as Washington, Fayette, Westmoreland and Somerset counties.
The region’s most pressing water problem is in Allegheny County, where even modest rainfall causes untreated sewage to overflow into the Allegheny, Monongahela and Ohio rivers from a 4,000-mile network of aging, overtaxed city and suburban lines, many of which were designed to carry both wastewater and storm water. The resulting high bacteria levels in rivers claims more than half of the recreational season each year, on average.
Treatment data illustrates just how inefficient the sewer system has become. ALCOSAN treats roughly 200 million gallons a day, but only bills for about 80 million gallons. “Only about 40 percent of the flow is actually going through somebody’s water meter,” said John Schombert, executive director of 3 Rivers Wet Weather, a project created to help communities address the sewer problem. “The rest comes from the municipalities and is water that has gotten into the system because of pipe conditions and through direct connections like springs and creeks.”
ALCOSAN and 83 county municipalities are under an EPA consent order to solve the problem by 2026. Doing so will require the largest public works program ever undertaken in the region.
The sanitary authority’s first plan to remove most of the more than 5 billion gallons of storm water and sewage overflows that overwhelm its treatment plant each year included a series of deep underground storage tunnels that would temporarily hold the excess during storms and gradually release it when the system regains the capacity to handle it.
But sticker shock led ALCOSAN to reconsider in 2012. The $3.6 billion cost, most of which would be borne by customers, would nearly triple the $262 average annual rate they now pay. That would consume more than 2 percent of the median household income in the authority’s service area, which, by the EPA’s own affordability index, is considered a high burden.
In its place, the authority last year proposed a scaled-down plan priced at $2.8 billion, which would still double the current water rates, but drop the burden on customers below 2 percent of the median household income. The latest plan would build smaller storage tunnels and fewer of them, eliminating those in the outlying communities in favor of containing overflows in or near the City of Pittsburgh, where volumes are the highest.
Whether the EPA will go along with Plan B is unclear. It would reduce sewage overflows into rivers and streams – perhaps capture as much as 85 percent near the city core – but uncontrolled overflows from outlying communities would prevent it from meeting water quality standards overall. The EPA is expected to rule on the amended plan this year.
The revised plan would likely delay improvements in some communities outside of the urban core. It might also offer an opportunity to revisit the idea of installing green infrastructure, such as rain gardens and permeable pavement, to reduce storm flow at its source – something that is missing from the current plan.
Source reduction also includes finding and fixing situations that contribute large volumes of water to the system. In some places, that includes creeks and springs that have been tied into sewer systems. In Pittsburgh, for example, the City-County Building stands on what was once a hill, which had been leveled. “If you look at the original maps, there were several streams that came off of that hillside,” said Schombert. “Well, there are no streams in Downtown Pittsburgh. Those streams on the maps are now in the ground, in the pipe and being conveyed to ALCOSAN.”