Potential Exposure: Environmental Monitoring




Source monitoring and emissions estimation do not tell us where the pollution goes after it leaves the source, e.g., to areas where many of us may be exposed to it.  They do not tell us what physical and chemical forms the pollutants ultimately takes on after they enters the air, water or land.[155]  Additionally, they do not measure pollution that may be entering our region from other areas, which is important for air pollution.[156]  Monitoring every individual pollution source would present serious logistical and cost issues.  We thus also rely upon monitoring the environmental media that transmit pollutants to humans: air, water, land and foods (e.g., fish).  In this section we discuss the health-related pollution monitoring data available for each of these four media, beginning with air. 

Ambient Air Monitoring

Ambient air monitoring essentially means the monitoring of “the air around us.”  Reports such as PennEnvironment’s Danger in the Air: Unhealthy Levels of Air Pollution in 2003 have made use of ambient monitoring data.[157]  In this section we first outline the types of pollution tracked, and where and in what format measurements are available.  While many pollutants are the same as those tracked through point source monitoring and the TRI, we also give additional explanation for important pollutants not already discussed.  We then discuss the details of the measurement systems within our region, to provide a better idea of what these data do and do not tell us.  Finally, we discuss some of the weaknesses of existing data, and data are simply not yet available.

General Ambient Monitoring Data for Allegheny County

The Allegheny County Health Department’s (ACHD) Air Quality Data Reports, now published quarterly along with an annual report, include data gathered from their monitoring sites with annual averages, year-to-date results and long-term trends.  Reports for 2002-2004 are available at the ACHD website.[158]  Several sources interviewed mention that this information is very valuable, and were concerned that the frequency of releases (formerly monthly) has recently been decreased due to ACHD funding and staffing cuts. 

The Pennsylvania Department of Environmental Protection’s (PADEP) annual reports include historical data from all of their monitoring sites.  Each year’s report includes a current year data summary and historical trends for the state excluding Philadelphia and Allegheny County.  Years 2002 and earlier are accessible through the “annual report” link on the Bureau of Air Quality’s homepage.[159], [160]

Criteria Pollutants: The Air Quality Index

Criteria pollutants[161] are defined above under the Source/Release section.  The Air Quality Index (AQI) reports describe the number of days per year that combined and specific criteria pollutants measured within each county were at levels considered good, moderate, unhealthy for sensitive populations, unhealthy, and hazardous.[162]  AQI daily reports by county and for the Pittsburgh Metropolitan Statistical area (MSA, see Appendix C: Map of Pittsburgh MSA) are available at the EPA AirNow website.[163]  The Allegheny County Health Department (ACHD) submits unofficial data for ozone and PM2.5 to the national AirNow system on an hourly basis (validated data are submitted later to the EPA), and also provides AQI levels each hour for continuously monitored pollutants via phone recording at 412-578-8179.[164]  The state PADEP website has AQI reports for the current 24-hour period, updated hourly, for 12 cities in the Southwestern Pennsylvania region.[165]  Note that while PADEP’s Southwestern Pennsylvania Index includes data from DEP monitoring sites throughout the region (but only one monitor from within Allegheny County, at the Carnegie Science Center), the EPA’s AirNow System includes ACHD data from a number of monitors within Allegheny County.[166]   Continuously updated hourly measurements for specific criteria pollutants, for all PADEP sites across Pennsylvania, are available through the “pollution levels” link on PADEP’s Bureau of Air Quality Homepage.[167]

More detailed ambient air quality data are at the Technology Transfer Network Air Quality System site.[168] The AirData site provides access to annual/quarterly summary data for monitoring and emissions estimates, as well as county-level annual AQI reports, and downloads of daily AQI data (over a one-year span for years 1994-2004) by county.[169]  For earlier years, e.g., 1994, AQI data are available for only 5 of the 10 counties in the region. 

A Criteria Pollutant of Special Concern:  Particulate Matter (PM)

Very small particulate matter (PM), including soot from coal-fired power plants and diesel exhausts, is a health concern because it is small enough to enter the innermost cavities of the lungs.  The two sizes monitored and reported under federal law are PM10 (particulate matter smaller than 10 microns in aerometric diameter) and PM2.5 (particulate matter smaller than 2.5 microns).  Following the EPA’s strengthening of PM2.5 guidelines, several western Pennsylvania counties including Allegheny County are out of compliance for PM2.5 levels.[170]  PM measured via ambient air monitoring is often very difficult to link back to a source because it rarely settles, often traveling across states, and it often undergoes chemical changes between release and capture by a monitor. 

Given the presence of several groups focusing upon air quality endeavors in the region, we likely know more about particulate matter in Pittsburgh than in most parts of the country.  Several years ago, the EPA and the National Energy Technology laboratory provided funding to establish a “PM Supersite” in Pittsburgh.  The 2000-2004 Pittsburgh Air Quality Study,[171] led by Carnegie Mellon University and involving investigators from more than a dozen other organizations, characterized PM in the Pittsburgh region, quantified the impact of various sources to particulate matter concentrations, and explored new methods of analyzing PM.  While Carnegie Mellon’s Air Quality Group has already published several works pertaining to the chemical composition and spatial variability of PM,[172] a great deal of analysis remains to be done on the data they collected, and the data themselves are not in a publicly useable format.[173]

The EPA has also provided funding to ACHD for two PM2.5 “speciation” sites: one on Lawrenceville, and one in Liberty Borough.  Speciation entails additional tests to determine particulate matter’s component chemical types so that it can potentially be linked back to a specific source.[174]  Speciation may also uncover different chemicals than were previously known to exist in that location—this occurred in Liberty Borough.[175]  PADEP currently conducts PM speciation in Florence and Greensburg,[176] and is “anticipating improving the network through the installation of additional continuous PM-2.5 analyzers.  The exact type, quantity and location of these analyzers within the Southwest [Pennsylvania region] is unknown at this time.”[177]

Hazardous Air Pollutants (HAPs)

HAPs are defined above under the Source/Release section.  Across the country, outdoor monitoring is largely limited to the six criteria pollutants;[178] there are currently fewer than 50 monitoring stations across the entire country that measure outdoor hazardous air pollutants.[179]  Federal regulations including the Clean Air Act do not mandate ambient monitoring of these chemicals.  The National-Scale Air Toxics Assessment (NATA),[180] released in 2002, utilized 1996 emissions data to estimate average annual outdoor concentrations for more than 30 HAPs.[181] 

Despite the lack of federal ambient monitoring requirements, the Allegheny County Health Department measures HAPs at three locations: (1), 48 HAPs are sampled at Flag Plaza for a 24-hour period once every six days,[182] (2), benzene is measured continuously at Liberty Borough, and (3) several HAPs are measured at Avalon and Stowe.  Details are listed in the Allegheny County Health Department’s Air Quality Quarterly Reports, available at their website.[183]

Monitoring System

Within Allegheny County, the Allegheny County Health Department (ACHD) monitors ambient air, and reports to the U.S. EPA.  The Pennsylvania Department of Environmental Protection (PADEP) also has one site at the Carnegie Science Center.   PADEP covers other counties in the Pittsburgh region.  As illustrated in Figure 4 below, the vast majority of our region’s criteria pollutant monitors are within Allegheny County.[184]

Figure 4: Criteria pollutant ambient air monitoring locations in the Pittsburgh region[185]


Total Monitoring Locations










Beaver Falls, Brighton Township, Hookstown, Vanport 















New Castle



Charleroi, Florence, Washington



Greensburg, Monessen, Murrysville

Region Total




*See Appendix G: Map of Allegheny County Health Department Air Monitors or ACHD’s Air Quality Reports[186] for a map of Allegheny County’s monitoring locations.


ACHD’s 21 monitoring sites continuously collect data every 10 seconds on the gaseous criteria pollutants, along with benzene, nitric oxide, and hydrogen sulfide.[187]  Averages by the minute and hour are compiled; and Air Quality Indices are calculated and reported hourly for particulate matter, sulfur dioxide, carbon monoxide and ozone.  Details of pollutants monitored at each site are in ACHD’s Quarterly Air Quality Report Ending December 2004.[188]

The EPA has four major requirements for ambient monitoring sites, which are followed (or exceeded) by the Allegheny County Health Department.[189]  The county must have:

·         At least one monitor indicating pollution coming in from outside the area (background pollution)

·         One monitor placed in the highest concentration area for each criteria pollutant (e.g., ozone)

·         At least one monitor near a major source of each criteria pollutant

·         At least one community-oriented site, e.g., in a high population area that isn’t necessarily near a source or a location of high pollution concentration.[190]


While ACHD manages all but one ambient air monitoring station within Allegheny county, PADEP  also manages a number of air monitors throughout the region.  See Appendix E: DEP Pittsburgh Area Ambient Monitoring Sites for additional details.  The pollutants monitored vary by site.  As mentioned above, the list of PADEP sites used to calculate the AQI for the Southwest Pennsylvania region are listed alongside the daily ratings at PADEP’s AQI website.[191]

To link together data from a number of systems including those described above, the Department of Energy’s National Energy Technology Laboratory (NETL) has hired several organizations to construct a database of ambient air quality information, collected throughout the Upper Ohio River Valley Region from 1999-2003.[192]  While not yet available to the public, the system will ultimately include a web-based interface with a variety of access, analysis, display and report generation tools.  More information is available at NETL’s website.[193]

Limitations of Air Monitoring Data[194]

Specific limitations already discussed, e.g., under particulate matter, are not reiterated here.

·         Cost limits the number of monitors that can be placed and maintained.

·         Given Pittsburgh’s varied topography, combined with the range of dissipation behavior of different airborne pollutants, concentrations can vary greatly within a short distance of a monitoring station.  Many air toxics are centered around a source, not spreading out much from them.  These will not be detected by distant ambient monitors.

·         Given limited resources, there is disagreement regarding the best placement of “community” monitors.  For example, if a number of people are living near a large pollution source, is it better to place it there, or in an area that may be more densely populated but further from (or not downwind from) a large pollution source?  Many densely populated areas not near a large pollution source aren’t being monitored.[195]

·         Nationwide, EPA has found that modeled annual average concentrations are typically lower than measured ambient concentrations.[196]

·         Because concentrations can vary greatly between and among monitoring locations, a “regional average” is not necessarily helpful, and no one monitoring station can represent a region.  This limits the usefulness of between-city comparisons, which may utilize the measurements of a single monitor from each city. 

·         Only a handful of regional sites can determine the components of particulate matter.

·         Many air toxics (HAPs) are not being measured at all, or only at a very limited number of sites.  We still don’t know the degree to which many more complex compounds, especially those that are highly toxic in small quantities, are present in ambient air.  This includes PAHs (polycyclic aromatic hydrocarbons), many of which are present in coke oven gas.[197]

·         Due to difficulties in setting up monitoring systems, the EPA lacked sufficient air quality data to designate PM 2.5 nonattainment sites using 3 years of data until 1999-2001 (and 2000-2002 for many sites).[198]

·         The publication frequency of ACHD’s Air Quality reports has been reduced from monthly to quarterly following funding and staffing cuts, and the data are not online in a queryable database format.

·         While Air Quality Index Measurements provide a simplified, public-friendly indicator, the monitors upon which they are based do not collect data at every location, and concentrations (and thus human exposure) may vary greatly between monitors.

·         AQI-related modeling has its limitations.  For example, a large site like Clairton Works may represent a “hot spot” that does not fit estimates and modeling assumptions for a larger area.

·         Monitoring of individual chemicals does not measure “cumulative impact,” i.e., how pollutants may build up and mix together to pose a potential threat to our health.[199]  This inability to measure cumulative impact also applies to other types of environmental monitoring, as well as source monitoring.


Case Study #3: The Neville Island and Mon Valley Bucket Brigades

In the Pittsburgh region, the Clean Water Fund (CWF) and Clean Water Action (CWA) have worked with two communities to sample air quality using “low-tech” bucket devices.  The “Bucket Brigades” then send these air samples to a lab for analysis, to determine what pollutants the residents are breathing. 

CWF and CWA formed the Neville Island Good Neighbor Committee in 1996, to unite residents in an area where nearly two dozen plants in roughly one square mile emit nearly one quarter of Allegheny County’s total toxic chemical air pollution.  While the Allegheny County Health Department (ACHD) monitored ambient air[200] for hydrogen sulfide, there was a concern that other unmonitored toxics might exist.  In 2001, Communities for a Better Environment, who designed the EPA-approved bucket sampling methodology, trained CWA and the Good Neighbor Committee on how to build the buckets and collect samples.[201], [202]

The eight samples the Bucket Brigade collected between March 2001 and January 2002 yielded 51 potentially hazardous chemicals, nine of which were well above EPA Risk-Based Concentrations and three other health-based standards.  Neither the state nor the county had ambient air standards for these chemicals.  As a result of the Bucket Brigade’s efforts, ACHD began to take air samples for several of the toxic chemicals in Avalon and Stowe Townships.  Relatedly, ACHD incorporated a “bad actor” provision into county air regulations, requiring companies to be in compliance with current air pollution permits before expanding or building new facilities.  The Bucket Brigade also made several monitoring-related recommendations.[203]

In the summer of 2004, CWA expanded the Bucket Brigade to the Mon Valley, sponsoring trainings for several communities near local coke, chemical and power plants.[204]  While ACHD currently monitors for several chemicals including hydrogen sulfide and benzene in this heavily industrialized area, CWA had received a number of citizen complaints regarding air quality.  CWA plans to complete analyses from sampling in communities including Elrama, Elizabeth, Clairton, and Glassport later this year.[205]

This example illustrates the following:

·         In heavily industrialized areas with large numbers of pollutants, existing monitoring systems and regulations may cover only a fraction of potentially harmful substances in the environment.

·         Citizen volunteers can be very useful for collecting data to fill environmental monitoring gaps, and to support advocacy for improved monitoring and regulation. 

·         Community organizing and advocacy organizations with environmental health know-how can also play a key role in working toward healthier environments. 

·         While such ad hoc efforts are not a complete replacement for more comprehensive environmental monitoring systems, communities and government agencies can benefit one another where data collection resources are limited.   


Land Monitoring

With exceptions (such as when children playing directly in or ingest soil), dangerous substances in soil generally do not become a health risk until they are mobilized via air or water, or absorbed through the roots of plants that humans or other animals eat.  In fact, the ground is the original source for numerous naturally occurring toxins (e.g., lead, mercury, coal.  From a public health perspective, air and water monitoring data are often more pertinent because they represent more direct paths to the human body.  In some cases, however, we may desire land monitoring data because a) there may be exceptionally high concentrations in an area, or toxins that are dangerous even in very small amounts (e.g., sites of former industrial operations, or brownfields), b) activities on a site, such as agriculture, may represent a direct path from land pollution to humans, c) materials in the ground may be a source of gases which easily find their way into our bodies (e.g., radon), or d) the site may near homes or a location of frequent human activity.   Here we discuss a few types of health-pertinent data that are more closely related to land than to water or air.  Groundwater and wells are discussed under “Water Monitoring,” and data on human-made elements of land such as roads and parking lots are covered under “Built Environment.”


As defined by the EPA, brownfields are “real property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant.”[206]  Brownfields may not pose enough of a public health risk to qualify for remediation funding under the federal Superfund program, but the clean-up costs may be great enough to deter developers.[207]  As Bartsch (2003) notes, there are major difficulties in quantifying the extent of brownfields: such words as “potential” make consistency in definition and counting total sites difficult, and the extent of contamination is unknown until a site is actually inspected.[208]  Inspections often do not occur until someone purchases or expresses interest in redeveloping a site, and wants a release of liability.[209]  

We may be exposed directly to pollutants via groundwater flows carrying toxins into wells, or dust raised during construction and redevelopment.  Additionally, children playing on brownfield sites may injure themselves on sharp objects and unsafe structures, come in contact with disintegrating chemical containers, or ingest toxins while disturbing contaminated soil.[210]  Brownfield assessment utilizes a risk-based source-pathway-receptor model, where the amount of risk is assumed to be lower where the pollutant has been removed altogether, where the pollutants’ believed path of transmission has been blocked (e.g., by covering a slag heap with several feet of dirt before building upon it), or where vulnerable organisms (e.g., humans) do not come near the site.  Ideally, brownfield remediation is done in a way that doesn’t add other negative environmental or health impacts.  For example, the Homestead Waterfront covered a great deal of former industrial sites with impervious parking lot surfaces.  At Summerset at Frick Park, a slag heap was covered with several feet of dirt before new homes were built atop it.

The Carnegie Mellon University/University of Pittsburgh Brownfields Center previously maintained a geographic information systems (GIS) application called “Pittsburgh RISES (Regional Industrial Sites Evaluation System), with developers as the primary intended audiences.  However, due to lack of funding, this system has not been updated since 2000.[211]  The PA Site Finder[212] is a “’one-stop-shop’ for brownfield buyers and sellers, and includes more than 250 sites in the Southwestern Pennsylvania region.[213]  The database includes locations and contact information, it includes very small properties of less than an acre, and it allows but does not require users to enter data into the environmental information fields (condition, assessments, and response actions).  Users receive a monetary incentive for posting sites online, which might motivate some to use a more liberal definition of “brownfield.”  PADEP’s eMapPA is also linked to this database, and can be used to map the included brownfields locations over a variety of other features.[214]  The EPA gave out several hundred grants for brownfields assessment pilot projects nationwide in the late 90’s and early 2000’s, several of which were in the Pittsburgh region.   While the sites of these studies are available online[215] along with grant property locations and types of grants,[216] the actual assessment results have not been compiled into a queryable or mappable database.

Several information gaps remain regarding the health of individuals near brownfield sites.  These include the following:[217]


·         The types and volumes of pollutants were emitted by the industries previously operating on a given site are often not available.  For long-term nearby residents, this may represent a greater health risk than that from materials still onsite.

·         Most existing brownfields data are on a site-by-site basis.  For example, we do not know the cumulative or aggregate impacts of numerous sites’ emissions into nearby rivers.   Our groundwater monitoring system is not complete enough to determine this.

·         We have little information on health risks due to the many materials that leach out of brownfields sites and change upon interacting with other materials, including those from nearby sites with different contaminants.

Illegal Dumpsites

Illegal dumping threatens our health in many ways.  Mosquitoes may breed in old tires, spreading West Nile Virus and other diseases.  Toxic chemicals may find their way into stream beds and rivers.  Hypodermic needles, prescription drugs and knives pose a threat to children and to homeless individuals who often scavenge and sleep near the sites.[218]  When individuals or organizations dump illegally, the burden of assessment and reporting often falls upon groups who actively monitor the environment. 

The Allegheny County chapter of PA CleanWays, has a one-person staff and relies largely upon volunteers.  This group recently conducted an illegal dumpsite survey.  In 2001-2002, they identified 141 dumpsites in the City of Pittsburgh, collecting such information as distance of the site from water, estimated cleanup difficulty, and presence of medical waste, car batteries, tires, mattresses and carcasses.[219]  They are coordinating their information collection efforts with the Southwestern Regional Office of PADEP, which has focused specifically upon illegal tire dumps since 1997.[220]  While PADEP’s data collection efforts are also limited due to having only 8 inspectors for the 10-county region, they are currently working to put the geographic coordinates of dump sites into a database,[221] and eventually wish to map them over streams, rivers and homes.[222]  These data will always be limited by organizational capacity to find dumpsites.  For example, sites in relatively rural areas (e.g., Greene, Fayette and Cambria counties) may take a long time to discover.

Due to lack of data or data connections, many questions about the relationships between illegal dumpsites and health remain unanswered.  What types and quantities of chemicals are leeching from illegal dumpsites into the ground and water?[223]  Are there clusters of blood borne[224] or respiratory illnesses near the dumpsites?  Are there increased emergency room visits for children and families living near dumpsites?  What health-related behavioral changes occur following neighborhood cleanups and interventions?  What is the relationship between community mental health and illegal dumping?  How many of us are at risk due to gardening on sites previously contaminated by illegal dumping?


Quarterly and annual data on municipal and residual waste[225] disposal, by county and individual facility, are available at the website of PADEP’s Bureau of Land Recycling and Waste Management, Division of Reporting and Fee Collection.[226]  Reports for 1988 through the first quarter of 2004 include several categories of waste, including infectious, construction, ash residue and asbestos.  Also at this site is a map and list of 15 landfills and incinerators in the Southwestern Pennsylvania region.[227]  Tonnage data are self-reported by the facilities, each of which is required to have scales to weigh incoming waste.  Inspectors can compare landfill records to remaining site capacity via physical survey or flyover.[228]  Municipal waste regulations require that landfills be inspected at least 12 times per year,[229] and auditors verify data only when where there is specific reason to believe that a site is misreporting.[230]  As for environmental monitoring, all landfills conduct groundwater (within 200 feet of site), surface water and air monitoring, in addition to other monitoring such as for radiation and leachates.  Further information on these data is held by PADEP’s regional offices.[231] 

Agricultural Soil Monitoring

Certain toxins in the soil (e.g., lead and other heavy metals) may be absorbed by food crops and then ingested by humans—or by animals then eaten by humans.  This may occur both on large commercial farming sites as well as on smaller urban farming and gardening sites.  In addition to toxic pesticides and herbicides, toxins could end up in the soil either from a previous use of the site (e.g., a house with lead paint), or from cumulative dustfall from nearby sources of air pollution.  As to our knowledge there does not exist a comprehensive database of soil quality for agricultural sites.  For those interested in collecting data for specific sites, Penn State’s Agricultural Analytical Services Lab provides soil testing for cadmium, copper, lead, nickel, chromium and zinc.[232]

Radon Gas

Radon, a colorless, odorless, radioactive gas, is currently one of the leading causes of lung cancer in the U.S.  It results from the natural deterioration of uranium in soil, and may enter homes through cracks and holes in foundations, or occasionally through wells.  Currently, roughly 40% of Pennsylvania homes are estimated to have radon levels above EPA’s recommended threshold for corrective action; and only about 10% of homes statewide have been tested.[233]  The PADEP Radon website’s Radon Test Results Data tool[234] allows querying by ZIP code (or partial ZIP code, e.g., to list all ZIP codes beginning with “152”) for the number of radon tests taken in basements of homes, and the minimum, maximum and average test results.  As levels within homes even in close proximity of one another may vary greatly, especially following corrective action such as venting, public health applications would likely require address-level data.

Water Monitoring

Water monitoring covers a broad range of pollutants, many of which can impact human health directly (e.g., biological pathogens), and many of which have significant but more indirect impacts (e.g., acid mine drainage).  Water condition data, such as stream flow[235] and temperature, are helpful for modeling and estimation but are not directly related to human health.  Because other very recent works cover a range of water quality data in greater depth,[236] we focus here upon data for a few topics directly related to human health. 

Water monitoring is vital because we can come in contact with water-borne pollutants in many ways.  We may directly contact river or stream water through recreational use (e.g., children playing in a stream, or families boating on the rivers).  Fishers come in direct contact with water, and many of us eat the meat of fish that have absorbed pollutants from the water.  We drink water that originates from local surface or groundwater sources, either through water treatment plants or from wells.  Statewide, major causes of health-related water contamination include agriculture (e.g., pesticides and waste), urban and stormwater runoff, and human waste from sewer system overflows.[237]

Outside of Allegheny County, most municipal- and county-level organizations in Pennsylvania do not collect water quality data, as the state has primary responsibility for drinking water and sewer system monitoring and regulation.  The Pennsylvania Department of Environmental Protection (PADEP) enforces the Clean Water Act, issuing permits and determining whether standards are met for three different uses: aquatic life use, human health use (risk posed by consumption of organisms or ingestion of water), and recreational use (risk associated with exposure to disease causing organisms through water contact).[238]  The last two uses are directly related to human health.  PADEP’s Water Quality Network has more than 140 monitoring stations on streams, rivers, and lakes statewide;[239] stream chemistry data can be accessed through the EPA’s online STORET system.[240] 

Within Allegheny County, the state contracts out to ACHD for various aspects of water monitoring.  The Three Rivers Wet Weather Demonstration Project,[241] a quasi-non-profit entity within ACHD, was created as the result of a negotiated consent decree to address the issue of sewer system overflows.  Some of their data are discussed above under the “Area Sources” subsection of “Source/Release.”  While a number of non-profit and volunteer groups[242] assist with monitoring efforts and compile data, their efforts are generally in the realm of ecological rather than public health related monitoring. 

Because Allegheny County faces several water quality issues, in 2002 the Allegheny County Conference on Community Development (ACCD) requested that the National Research Council (NRC)’s Water Science and Technology Board form a Committee on Water Quality Improvement for the Pittsburgh Region.  Their 2005 report, spanning more than 250 pages, states the following in its introduction: “…[I]nadequacies in the type and extent of water quality data available…prevented the committee from assessing the full extent of adverse effects due to pollution.  Almost all of the water quality data available …were derived from single studies in specific areas for limited durations.  Recently, several agencies have expanded water quality data collection…although there appears to be little coordination…therefore, it is difficult to fully identify the sources of pollution…to assess the extent of adverse effects, and to prioritize remediation efforts.” [243]  They recommend several data-related steps including quantifying water pollution loads and modeling their relationships to water quality, undertaking coordinated basin-wide monitoring (including biological monitoring) and modeling to estimate the amounts and relative impacts of various sources of pollutants entering surface water and groundwater, expanding sewer system and stormwater modeling activities, and integrating assessment and response with PADEP’s process of establishing total maximum daily loads (TMDLs) for impaired streams, which is required by the Clean Water Act.

Rivers and Streams—Pathogens

Pennsylvania has more than 83,000 miles of free-flowing surface waters, and Allegheny County alone has more than 90 miles of rivers and 2,000 miles of streams.[244]  Several types of waterborne pathogens may affect our health: protozoans such as Cryptosporidium parvum and Giardia lamblia, bacteria such as E. Coli, and viruses causing diarrhea and other symptoms.[245]  While not the only source of pathogens, wet weather sewer overflows alone are a significant problem in the Pittsburgh region.[246]  However, the vast majority of collection endeavors, at both the state and regional levels, focus on the physical and chemical aspects of water quality, but ignore pathogen contamination.  Additionally, there exists no database (or host agency) where pathogenic contamination data can be maintained and accessed on a regular basis over time and geography, even though law mandates such collection.[247], [248]  Here we explain a few key points about pathogen monitoring, describe what endeavors do exist to compile this information, and outline a few major weaknesses/gaps in the information base.

Because we do not know the total flow or concentrations from the numerous sources of contamination, we rely upon ambient monitoring of rivers and streams.  This is even more the case given that the states and the federal EPA have shifted regulatory focus from individual point-source dischargers of waste in water to the reduction of overall pollution on bodies of water (total Maximum Daily Loads, or TMDLs).[249]  Additionally, rather than try to monitor all potentially harmful microorganisms directly, we usually rely upon “indicator organisms” for pathogen monitoring:

“Members of two bacteria groups, coliforms and fecal streptococci, are used as indicators of possible sewage contamination because they are commonly found in human and animal feces.  Although they are generally not harmful themselves, they indicate the possible presence of pathogenic (disease-causing) bacteria, viruses, and protozoans that also live in human and animal digestive systems.  Therefore, their presence in streams suggests that pathogenic microorganisms might also be present and that swimming and eating shellfish might be a health risk.” [250]


An interdisciplinary project within Carnegie Mellon University’s STUDIO for Creative Inquiry,[251] 3 Rivers 2nd Nature (3R2N) has collected samples along 29 river transects[252] over several years, as well as 53 streams, suggesting that bacteriological problems exist in both rivers and streams.[253]  Through this work, they have identified 18 streams with significant water quality issues.  The most extreme cases have average concentrations exceeding 400,000 and 80,000 Colony Forming Units per 100ml respectively[254]—to put this in perspective, the PADEP states that “no more than 10% of the total samples taken during a 30-day period may exceed 400 per 100ml.”[255]  Some of the 3R2N data, in report and map format, is available on their website.[256]

Section 305(b) of the Clean Water Act requires states to report water quality information gathered under monitoring programs every two years, and Section 303(d) requires a listing of water bodies that are “impaired” for aquatic life, human health or recreation.  This information was last reported for Pennsylvania in the 2004 Pennsylvania Integrated water Quality Monitoring and Assessment Report.[257]  Note that this list includes only bodies that are impaired after required water pollution control technologies have been applied (e.g., a stream affected by a point source in violation of limits would not be included).[258]  Of groups monitoring streams outside of Allegheny County for bacteriological levels, at least 6 submitted full datasets to DEP; some of this information was used in the report.[259]

The Ohio River Valley Water Sanitation commission (ORSANCO) regularly monitors the Ohio River between Pittsburgh and Evansville, Indiana for fecal coliform and E.coli.  Per-sample data for the 1998-2004 recreational seasons in table format, are available at the ORSANCO website.[260] While the data are queryable by location, month and year, the samples are taken only five times monthly, at six stations, and only during the recreational season.  More comprehensive data are described in their “Quality Monitor” reports available at the same website, but as of March 2005 the reports were available for six-month periods only through December 2002.

From July to September 2001, the USGS and the Allegheny County Health Department tested the Allegheny, Monongahela and Ohio Rivers for fecal indicator bacteria.  They collected water quality samples and river discharge measurements at 5 sites on the three rivers during dry, mixed-, and wet-weather periods.  Findings included that specifically during wet weather events, fecal coliform, E. coli and enterococci exceeded federal water-quality standards in 56, 71 and 81 percent of samples, respectively.  These data are available at the USGS website.[261]  However, while this study provided useful information on major rivers, it did not include streams, of which there are over 2000 miles in Allegheny County alone.[262]

Outside of the major limitations outlined at the beginning of this section, several weaknesses and gaps still exist in our base of pathogen indicator monitoring data:

·         We do not know the accuracy with which an intermittent sample represents the water body’s overall concentration.

·         We do not know how often other potentially harmful organisms may or may not be present when we detect indicator organisms—this is particularly an issue with viruses and protozoan parasites.[263]  The EPA now recommends E. coli and enterococci as indicator organisms, rather than fecal coliform, as an indicator because the latter has been found to have a lower correlation with swimming-associated gastroenteritis.[264]  However, Pennsylvania still utilizes fecal coliform as its recreational water pollution indicator—possible reasons for this are outlined elsewhere.[265]  A change within Pennsylvania has been discussed, but may not occur until 2008.[266] 

·         We do not know how well water transmits certain types of harmful organisms such as viruses.[267]

·         Tests directly identifying pathogens such as crypotospordia and ghirardia do not indicate whether they are still alive (and thus pose an actual health risk)—to determine this, additional tests (and costs) would be required.[268]

·         Although fecal contamination is very likely to have human sources once it is above a certain level, it can sometimes be difficult to judge whether the source of fecal contamination is human or animal.[269]

Drinking Water Processing Plants

Most of us in the Pittsburgh region rely upon public water services drawing from surface water sources such as the three rivers, Beaver Run, and Indian Creek.  Within Southwestern Pennsylvania counties, roughly 70% of us are served by such sources, with 11% served by public groundwater and 19% by private wells or springs.[270] 

Under the federal Safe Drinking Water Act, community drinking water utilities are required to test and report water output.  They must mail copies of annual water quality reports (also called “Consumer Confidence Reports”) to each customer, and are required to post the reports on a publicly-accessible site only if they serve 100,000 or more customers.[271]  Links to Allegheny County annual drinking water quality reports (year 2003, as of the time of this writing) are available at the Allegheny County Health Department’s website.[272]  Additional reports for selected water systems in Pennsylvania, including Westmoreland County Municipal Authority, are available at the PADEP website.[273]  Monitored substances include potentially harmful by-products of drinking water chlorination, microbiological contaminants such as fecal coliform bacteria, and metals such as lead, arsenic and chromium.[274]  The data include annual ranges of measured concentrations and a “yes/no” regarding whether federal standards were violated at any point.  The EPA Safe Drinking Water System (SDWIS)[275] database includes instances of health-based, monitoring and reporting violations for 1993-2004, and is searchable by water system name, state, county and size of population served.

While municipal drinking water systems generally do an excellent job of filtering out regulated substances, there are not yet regulations for a large number of chemicals in drinking water that may be harmful; thus, these chemicals are not regularly monitored—this includes such chemicals as perchlorate, the herbicide DCPA (dimethyl tetrachloroterephthalate),[276] and the gasoline additive MTBE (methyl tertiary-butyl ether).[277]  We do not know the relative extent to which various hormonal agents and antibiotics are present in the environment, be it in drinking water or elsewhere.[278]  Additionally, drinking water plants are not required to apply for permits, which would require them to report their whole process and monitor the various chemicals utilized.  Finally, because output monitoring is not continuous, sudden or temporary spikes in chemicals may not show up in the data.[279]

Wells and Groundwater[280]

While the other subsections in this section deal with specific types of pollutants, we treat wells separately because they present a significant potential health issue in rural areas.[281]  Additionally, in terms of volume, they represent one of the most important direct water exposures to humans.

Even though residents in developed areas rely upon public water services, nearly one million Pennsylvania households utilize private water supplies.[282]  Within Southwestern Pennsylvania, nearly 30%, or 800,000, residents utilize public or private wells.[283]  According to several experts, lack of information on well water quality, especially in rural areas, is a serious issue.  With limited exceptions, Pennsylvania law does not require testing of well water quality; and groundwater monitoring is required under the Safe Drinking Water Act only if an area is known to impact a public drinking water source.  The New Jersey Department of Environmental Protection offers a model for improved well water data collection;[284] information including initial testing results for more than 5,100 wells is available at its Private Well Testing Act page.[285] 

The National Research Council’s 2005 report notes that where data are available, “private wells show significant variability in terms of microbial contamination, and the effects of mining are apparent in some areas…”  Although there is no recent evidence linking Southwestern Pennsylvania groundwater quality with any waterborne disease outbreak, “significant gaps exist in public health monitoring, thus preventing an adequate assessment of possible endemic waterborne disease occurrences.”  According to one expert, not a great deal is currently known about the behavior of underground water “plumes” i.e., the geospatial dispersion of underground water, in Pennsylvania.[286]  This may impact sources such as well water.

In a study mentioned previously, the U.S. Geological Survey tested groundwater samples from 86 sites near storage tanks and 359 ambient groundwater samples throughout Pennsylvania for MTBE (methyl tertiary-butyl ether) concentrations between 1998 and 2001.[287], [288]  To complement the more localized monitoring done near permitted facilities or public water supplies, PADEP monitors groundwater on a watershed level, including several groundwater basins in Allegheny County.  The report “Summary of Groundwater Quality Monitoring Data (1985-1997) from Pennsylvania’s Ambient and Fixed Station Network (FSN) Monitoring Program” includes aggregate data from numerous groundwater quality monitoring points within five basins within northern Allegheny County, and extending slightly into Beaver, Butler and Westmoreland counties.[289]  Toxins such as lead, mercury and arsenic are included in their data.  The Pennsylvania Spatial Data Access (PaSDA) website features a downloadable geographic information systems (GIS) file with locations of points sampled for this study,[290] and PADEP’s “eMap PA” online mapping tool plots the locations of groundwater monitoring points statewide.[291]

Toxic Metals

            Metals such as arsenic, lead, cadmium, chromium and mercury have all been linked to adverse outcomes in humans, including cancer and irreversible neurological damage.[292]  The U.S. Geological Survey study described under “Pesticides” collected information on each of these metals, detecting them at varying levels in bed sediment across the region.[293]  In that study, bed sediment was sampled not with direct human effects in mind, but because contaminated sediment can negatively effect aquatic life.[294]


From 1994-2000, the U.S. Geological Survey (USGS) collected data on surface water and ground water quality through the Allegheny-Monongahela National Water-Quality Assessment (NAWQA).  This included monitoring of water and fish tissue for volatile organic compounds (VOCs), pesticides, metals such as mercury, and nutrients.[295]  Data are available at the study’s website.[296]  Due to the size of the study area, only a limited number of sites were in the Pittsburgh region.  However, two of these sites were sampled intensively for pesticides—an analysis of one suggested that residential lawn care products, not just agricultural applications, are a significant source for that area.[297]

Pharmaceutical and Personal Care Products (PPCPs)

As mentioned under drinking water source monitoring, we do not yet know the relative extent to which various hormonal agents and antibiotics are present in the environment.[298]  Products may enter the environment via human excretion (i.e., when the body does not completely metabolize them), or through the improper disposal of industrial waste.  If they are not filtered out via natural or human treatment processes, they may find their way into other people via drinking water or via animals that are eaten by humans.  To establish a baseline as part of the “Emerging Contaminants Project,” the U.S. Geological Survey tested water samples from nearly 200 points (streams, wells and effluent samples) nationwide for the following types of substances between 1999 and 2000: human and veterinary pharmaceuticals, industrial and household wastewater products,[299] and reproductive and steroidal hormones.  Links to this study and a number of related publications, along with an outline of research needs and gaps, are at the Environmental Protection Agency’s “Pharmaceutical and Personal Care Products (PPCPs) as Environmental Pollutants” page.[300] 

Animal Biomonitoring: The Example of Fish

The Pennsylvania Integrated Water Quality Monitoring and Assessment[301] is a water quality survey carried out by PADEP that examines toxic substances and quality of waterways.  Part of the survey methodology includes fish tissue sampling for PCB’s, selected heavy metals including mercury and lead, and twenty different pesticide compounds.  Samples are generally collected during periods of low flow between August and October when reproduction is complete and a full exposure to potential toxins has occurred.  For some species, samples are collected in the spring. A normal sample consists of 10 scaled, skin-on fillets from a composite of five individuals of the fish species.  The target species is normally a representative, recreationally important species for the water body being sampled, although Channel catfish or bullhead samples consist of 10 skinless fillets and American eel samples consist of five 1-inch sections from each skinned and gutted eel.   All fish in the composite should be of the same species and approximate size.  Each sample is ground three times, with the tissue mixed between grinding to ensure a homogenous sample.  Four packets of tissue are prepared, wrapped in aluminum foil, numbered and refrozen.  These four packets are used as follows: one for metals analysis, one for PCB analysis, one for pesticide analysis, and one as backup for re-analysis, if needed. This identifies substances in PA waterways, most of which are in concordance with ATSDR substances. 

The water body assessment and data evaluation is a continuous process but not all waterways are included in the DEP’s two-year reporting cycles.  Specific waterways are targeted that have either not been assessed, have been identified as impaired and monitoring is used to measure improvement, or are being monitored to reassess no impairment.  The 2004 Integrated Report was developed using information from stream and lake surveys and other sources, including DEP’s Statewide Surface Water Assessment Program, the Non-point Source Program, and existing and readily available data submitted by external groups and agencies.  The DEP also encourages community-based citizen volunteer monitoring. 

Reel Danger: Power Plant Mercury Pollution and the Fish We Eat was a study carried out by PennEnvironment Research and Policy Center.[302]  The study utilized the first two years of data from the EPA’s National Study of Chemical Residues in Lake Fish Tissue.  The EPA study selected a representative sample of 500 of the estimated 270,000 lakes and reservoirs in the continental U.S.  At each lake, researchers collected composite samples during the summer and fall of one predator species and one bottom-dwelling species, each consisting of approximately five adult fish of the same species and of similar size.  Researchers analyzed fillets for the predator fish and whole bodies for the bottom-dweller fish to measure concentrations of 268 chemicals in the fish tissue.

Key findings of the study were that all of the fish samples were contaminated with mercury.  Fifty-five (55) percent of the fish samples were contaminated with mercury at levels that exceed EPA’s “safe” limit for women of average weight who eat fish twice a week.  Seventy-six (76) percent of the fish samples exceeded the safe mercury limit for children of average weight under age three who fish twice a week; 63 percent of fish samples exceeded the limit for children ages three to five years; and 47 percent of the fish samples exceeded the limit for children six to eight years.  Eighty (80) percent of the predator fish samples contained mercury levels exceeding EPA’s safe limit for women. In 18 states, 100 percent of the predator fish samples exceeded this limit. 

Fishing for Trouble, another report generated by PennEnvironment, indicated gaps in data for EPA mercury advisories to the public.[303]  For a number of advisories, states failed to include data on the acreage or number of miles of a water body under advisory. Thus, assuming that EPA’s data is accurate, the calculation for geographic area under advisory by state is an underestimate of the true geographic area under advisory.  Some of the EPA data for advisories is missing units (e.g. acres or miles). For purposes of the summary data in the report, it was assumed that if a state listed its other advisories for a specific water body type (e.g. lakes) using specific units (e.g. acres), then the state used the same unit for that type of water body across the state.

Another source of fish tissue samples is the U.S. EPA’s STORET (short for STOrage and RETrieval) online database.[304]  This system contains data collected beginning in 1999, including biological, chemical, and physical data on surface and ground water collected by federal, state and local agencies, Indian Tribes, volunteer groups, academics, and others. All 50 States, territories, and jurisdictions of the U.S. are represented in these systems.