Monday, December 31, 2012

What’s EPA Doing about Fracking?

EPA will be holding a webinar on their fracking studies that includes research approach, status, and next steps if you are interested. The webinar will be presented on two different days, Thursday, January 3rd and Friday, January 4th 2013. Jeanne Briskin, Hydraulic Fracturing Research Coordinator, Office of Science Policy, Office of Research and Development will be the instructor and the webinars are: on January 3, 2013, 2:00 PM - 3:00 PM, EST and January 4, 2013, 12:00 PM - 1:00 PM, EST. Just click through on the links and sign up.

The United States has vast reserves of natural gas within shale and rock formations. During the past decade, extracting that gas has become commercially viable as a result of the advances made in horizontal drilling and hydraulic fracturing (fracking) techniques. With the rapid increase in fracking has come the increase in concerns about its potential impacts on drinking water. In response to public concern ignited by the film Gasland and protests by anti-fracking groups, the US House of Representatives requested that the US Environmental Protection Agency (EPA) examine the relationship between fracking and drinking water resources in 2009. In 2011, the EPA began a series of research projects into the impacts and potential impacts of fracking on water. Also, in April 2012 EPA released the first federal air rules for natural gas wells that are hydraulically fractured, specificallyvrequiring operators of new fractured natural gas wells to use “green completion,” which is a series of technologies and practices to capture natural gas and other volatile substance that might otherwise escape the well during the completion period when most volatile release takes place.

Hydraulic fracturing has its own water cycle and involves the pressurized injection of fluids commonly made up of mostly water and chemical additives into a geologic formation. The pressure used exceeds the rock strength and the fluid opens or enlarges fractures in the rock. As the formation is fractured, a “propping agent,” such as sand or ceramic beads, is pumped into the fractures to keep them from closing as the pumping pressure is released. The fracturing fluids (water and chemical additives) are partially recovered and returned to the surface. Natural gas will flow from pores and fractures in the rock into the wells allowing for enhanced access to the methane reserve. Two to five million gallons of water are typically necessary to frack one horizontal well in a shale formation. Water used for fracturing fluids is acquired from surface water or groundwater in the local area. Wastewaters from the hydraulic fracturing process (flowback or water produced in the well) may be disposed in several ways. The water that flows back after fracturing may be returned underground using injection well, discharged to surface waters after treatment to remove contaminants, or applied to land surfaces. Not all fracturing fluids injected into the geologic formation during hydraulic fracturing are recovered. The EPA estimates that the fluids recovered range from 15-80% of the volume injected depending on the site. The long term fate of any residual fluid has not been studied.  

Each stage of the fracking water cycle is a potential area for impact to drinking water supplies especially from human error and irresponsibly and improperly handling chemicals and contaminated water and poorly managing and protecting our water resources.  The steps in the fracking water cycle are:
Water acquisition. Chemical mixing. Pressurized Well injection. Flowback and produced water (collectively referred to as “hydraulic fracturing wastewater”) recovery. Wastewater treatment and disposal. Geology, hydrology and human behavior will produce vastly different outcomes for different regions of the county and different gas companies.
from US EPA

EPA is engaged in a number of research projects that will be the basis of their actions and future regulations for oil and gas operations. Whether the EPA will regulate oil and gas exploration nationally or leave the oversight in the hands of the states is an open question. There is an argument that water resources and geology are very local phenomena and cannot be generalized over the nation and that hydraulic fracturing should remain under local oversight. The 2005 energy law exempts fracking from the Safe Drinking Water Act based on the 2004 EPA study “Evaluation of Impacts to Underground Sources of Drinking Water by Hydraulic Fracturing of Coalbed Methane Reservoirs.” In that report EPA reviewed 11 major coal basins mined for coalbed methane and saw no conclusive evidence that water quality degradation on underground drinking water supplies had occurred as a direct result of the injection of hydraulic fracturing fluids, but fracking of coalbeds generally involves a fraction of the water used in hydraulic fracking of shale gas.

The current fracking projects are a series of studies. Existing Data from multiple sources have been obtained for review and analysis. Well construction and hydraulic fracturing records provided by well drillers are being reviewed for 333 oil and gas wells across the United States; data within these records are being examined to assess the effectiveness of current well construction practices at containing gases and liquids before, during, and after hydraulic fracturing. In addition information on the chemicals and practices used in hydraulic fracturing has been collected from nine companies that hydraulically fractured a total of 24,925 wells between September 2009 and October 2010. Data on causes and volumes of spills of hydraulic fracturing fluids and wastewater are being collected and reviewed from state spill databases.

Computer models are being developed to identify conditions that may lead to impacts on drinking water resources from hydraulic fracturing. The EPA has created hypothetical scenarios for  water acquisition, well injection, and wastewater treatment and waste disposal stages of the water cycle that they hope to have the models evaluate. Computer models are also being used to explore the possibility of subsurface gas and fluid migration from deep shale formations to overlying aquifers in six different scenarios. The effectiveness of the models would be dependent on how closely the model predicts transport behavior in rock and shale and the similarity in behavior of different formations.

Laboratory studies are being performed to identifying potential impacts of inadequately treating hydraulic fracturing wastewater and discharging it to rivers. Experiments are being designed to test how well common wastewater treatment processes remove selected contaminants from hydraulic fracturing wastewater, including radium and other metals. Since wastewater treatment plants are not designed to remove more than biological waste and bacteria, any removal of fracking chemicals and contaminants would be incidental. I do not expect that wastewater treatment plants would be able to treat flowback water for the contaminants associated with geological formations and fracking chemicals.

The EPA has identified chemicals used in hydraulic fracturing fluids from 2005 to 2011 and chemicals found in flowback and produced water. The EPA is performing toxicity assessments based on chemical, physical, and toxicological properties for chemicals with known chemical structures. Existing toxicology models are being used to estimate properties in cases where information is not available. The important thing that EPA is doing is bringing together all the data and previous work to get as complete picture of what we know about how hydraulic fracturing may be impacting our water resources.

Thursday, December 27, 2012

Prince William Health District Offers Essential Services to Well Owners

Last week I went down to Woodbridge to meet with Marcus Haynes, who is an Environmental Health Specialist with the Prince William Health District and the “water and well guy” for the county.  The Prince William Health District is a branch office of the Virginia Department of Health that administers the health related laws throughout the state. Marcus is part of a six person team located in Building 5 at the Prince William County Complex in Woodbridge that administers the health laws and regulations relating to private water supplies and sewage systems, water well construction regulations, and septic and alternative on-site sewage system construction and operation regulations. In addition, the PW Health District provides help and guidance for private well and traditional and alternative septic systems.

Marcus has been with the PW Health District since 1977, starting on the job the day Prince William County first implemented county wide well construction regulations. Those regulations were very progressive for their time and quite similar to the current sate wide regulation implemented in 1992 and still in effect today. Through experience, additional training and certification, Marcuse has an almost encyclopedic knowledge about the groundwater in our county and water wells in general. He knows the fracture density and thus groundwater availability in all of the county and thus knows where well yields are a problem. In years past he worked in conjunction with the US Geological Survey to develop their study of the extent of chlorinated solvent contamination in the Culpeper groundwater basin in Prince William County from the historic operations of IBM Corp.  
From 1970 to 1975, IBM used chlorinated solvents to degrease electrical components at its plant in Manassas, Virginia. Spills and poor disposal and containment practices contaminated the groundwater. The PW Health District was instrumental in identifying that the contamination had reached the (now abandoned) public supply wells and private wells serving about 32,000 people. Ultimately, IBM's funded the study of the groundwater (1), installed monitoring wells and under RCRA (federal Resource Conservation and Recovery Act) removed the contaminated soil and contained and/ or eliminated the contaminated groundwater. IBM connected homes with contaminated wells to Prince William County's water supply system which obtained other sources for water supply. It is hoped that these days pollution problems of this magnitude will be prevented by the modern web of environmental and health regulations, but it was with the help of the PW Health District that the problem was identified.

The mission of the PW Health District has remained consistent over the years; to protect the Public Health and the water resources of the Commonwealth. However the understanding of the interconnection of surface water, groundwater, and the increase in population and the density within the county of on-site private water and sewage treatment systems has changed the emphasis and nature of their work. There was a time when the homeowner was more directly involved in the construction of their water wells and septic/ on-site sewage systems and Marcus and the Environmental Health team did all certifications and dealt with the homeowner directly. These days many of these steps have been outsourced to the private sector while staff addresses problems, VPDES permit system and critical issues. Though each well requires a permit, the homeowner can have the well driller act as their agent and site visit, inspections and sampling can also be performed by the private sector. In subdivisions like mine, the well and water systems were built by four different subcontractors and the coordination depended on the interest, knowledge and skill of the project foreman. The homeowner is removed from the process until there is a problem and then lacking any background or knowledge the homeowner does not know where to turn. If you have a problem with a private water or waste system, call the PW Health District. If you have a concerns or want background information you might call me at the Virginia Master Well Owners Network for information.

Marcus would like to see the homeowner’s relationship with the PW Health District begin before the even purchasing a home. Information on all private wells drilled in the county after 1977 are in their files. The PW Health District has detailed files on over 20,000 wells. Before buying a home with a well you should have the well drillers log in hand. The “Water Well Completion Report” can tell you the age of the well, the depth of the well and casing, the approximate water zones and the yield at completion. These are the most basic facts needed to evaluate a well and water system.   The best place for all homeowners with private drinking wells to start is to call or email the PW Health District and request a copy of the “Water Well Completion Report” and ask if there is other information in the file. You should also take a look at the brochure “TenTips for Managing Your Private Well Water Supply.” Prince William Office of Internet Technology is working to computerize the Environmental Health Records in the GIS system, but for now you will have to call and ask them to email (or fax) you the information. Marcus’ phone number is (703) 792-6343 and his email is (He is pretty responsive to routine requests, but water well problems move to the top of the pack and get fast turnaround. I have waited on hold while he has scanned and emailed me a copy of the “Water Well Completion Report” for a VAMWON client in stationed in Afghanistan with a water well in the county that had stopped working.)

When a well is drilled the only water sampling that takes place is for a coliform bacteria test. There are many chemicals and naturally occurring contaminants that could make water unpalatable or unhealthy. Before buying a home you need to perform a more extensive testing of the water. For this you can sample and test using a private certified laboratory or you can have the Health District sample your water for you. The Health District charges $80-85 for the first chemical or contaminant and $20 for each additional contaminant. The Virginia Household Water Quality Program recommends that water be analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria (if coliform is present) and any industrial or agricultural chemicals that may be of concern at the particular location. That can add up to quite a bill, but a home is probably the most expensive purchase you will ever make- verify the quality of the water.

Marcus also recommends that before buying a home with a private well you verify the capacity and the condition of the well. His rule of thumb is 5 gallons/minute is a safe yield to supply on-demand water for a typical household, but homes can have much lower yielding wells and still provide adequate water at least sometimes. Be aware that over time the yield of a well falls and what was an adequate well 20 years ago may not be now. Groundwater enters a well through fractures in the bedrock and overtime debris, particles, and minerals clog up the fractures and the well production falls. Marcus said that the drop in water recharge rate could be 40-50% or more over 20-30 years. A low yielding well might have a functional life of only 25 years. So, if you are buying a home with an older well having a well driller perform an accurate assessment of the well’s capacity would be important. A well recharge can be estimated by running water from the pump and measuring the top of the water level in the well. If it does not change, then the well recharges faster than the pump rate. If the level is falling then the each foot in a typical 6 inch cased well represents about 1.5 gallons.  A more accurate rate to determine the recharge rate is to use a compressor to blow all the water (and deposits at the bottom of the well) out of the well and time how long it takes the well column to recharge. The well driller can also examine the condition of the casing, wiring, pump and the well components in the house. 

A private well owner is responsible for their water supply. The PW Health District is a treasure, providing incredible expertise and valuable services for well and septic system owners throughout the county. 

(1)    Nelms, D.L., and Richardson, D.L., 1990, Geohydrology and the occurrence of volatile-organic compounds in ground water, Culpeper basin of Prince William County, Virginia: U.S. Geological Survey Water-Resources Investigations Report. This report funded by IBM is still a fabulous resource to understanding the groundwater in Prince William County. 

Monday, December 24, 2012

The Washington Aqueduct Searching for the Best Possible Drinking Water

The Washington Aqueduct is a federally owned and operated by the Army Corp of Engineers. The Aqueduct consists of the Dalecarlia Reservoir and Water Treatment Plant, the Georgetown Reservoir, and the McMillan Reservoir and Water Treatment Plant. The Washington Aqueduct draws water from the Potomac River and treats it to provide finished drinking water to the water distribution companies that buy water from them. Thomas Jocobus, a civilian employee of the Army Corp of Engineers is the General Manager and the Aqueduct produces an average of 155 million gallons of water per day which it sell to the District of Columbia (about 75%), Arlington County, Virginia (about 15%), and the City of Falls Church, Virginia (10%).

The Washington Aqueduct is a very conservative organization reflecting its structure, management, and response to events of the past. Water systems consist of three systems: The first is the water treatment systems that draw water from the source and treats it to meet the US EPA Safe Drinking Water Act standards (SDWA). The second is the water delivery system that moves the water from the finished water storage through the water mains and throughout the community so that there will be on demand water and adequate water for firefighting. The third is the plumbing systems in homes and building that deliver water to your sink, toilet or shower.

Somewhere in the past the Washington Aqueduct had begun to view their mission as providing finished water that met all EPA SDWA requirements. After all, (unlike most water utilities that are regulated by state regulators) EPA Region 3 was their direct regulator and they were attentive and responsive to the regulatory requirement and deeply concerned about the quality and cost of the finished water they sold.  All the costs of the Aqueduct operations are directly passed on to wholesale customers. In the 1990’s something happened to remind the Aqueduct that really they are in the public health (and fire safety) business and that their operations could not be viewed separately from the water delivery and plumbing systems that ultimately brought water to the households and businesses that bought water  from the distribution companies. What happened was chloramine.
from DC Water

In 1994 amendments to the Clean Water Act SDWA resulted in changing from chlorine to chloramine for disinfection. The EPA issued regulations concerning disinfectionby-products formed when chlorine (used for a hundred years) reacts with organic matter in drinking water; the EPA considered these byproducts to be a potential health threat. Chloramines do not produce disinfection byproducts. The treatment process for the Washington Aqueduct was changed to add ammonia after primary disinfection to react with the remaining chlorine to prevent the formation of disinfection byproducts (haloacetic acids and trihalomethanes). When planning the chloramine project as advised by  EPA guidance manual the Aqueduct considered the possibility that the disinfectant change would increase the level of nitrification in the distribution system. Such an increase could cause a lowering of pH in the distribution system, increasing the possibility of corrosion. The Aqueduct put a plan in place to minimize the potential for nitrification and monitored for nitrification for six months following conversion. Unfortunately, corrosion was not caused by nitrification.  Shortly after the change, increasing pipe failures and levels of lead began appearing in the homes of Washington DC residents. It turns out chloramine-treated water picks up lead from pipes and solder and does not release it, resulting in elevated levels and deterioration of the pipes. Extreme lead concentration began appearing in Washington DC homes and water delivery pipe and plumbing systems began to fail at an accelerated rate.
Dr. Marc Edwards a MacArthur Prize winning professor of engineering at Virginia Tech ultimately  identified the cause and solution of the increasing incidence of leaks in copper water pipes. The lead problem was addressed by the Washington Aqueduct adding additional treatment steps to add orthophosphate and tightly control the pH of the water.  Orthophosphate controls corrosion in pipes, service lines, and household plumbing throughout the distribution system. It works by building up a thin film of insoluble material in lead, copper, and iron pipes and fixtures. This thin film acts a barrier to prevent leaching of metals into the water, but only works in a narrow pH range. Calcium hydroxide (lime) is also added to adjust the pH of the water to ensure optimal performance of the orthophosphate. In addition, DC WASA spent $97 million to replace a portion of 15,000 pipes and 2,000 full pipe replacements.

The change in the water treatment process prevents the finished water from dissolving lead in the water mains, solder joints, and fixtures. The changes in the operation of the Washington Aqueduct were more profound. The Aqueduct had to rethink the management of their relationship with their customers, how had they made a change in the water treatment without testing the impact on all the other water systems? That is unlikely to ever happen again.  The Washington Aqueduct's customers (District of Columbia Water and Sewer Authority, Arlington County, and the City of Falls Church) entered into a memorandum of understanding with the U.S. Army Corps of Engineers that restructured the business relationship and created the Wholesale Customer Board and Technical Committee to oversee and approve Washington Aqueduct's operating and capital budgets and long term strategy.

The Washington Aqueduct’s official mission became to provide the “best possible” drinking water while: Minimizing any negative effects on the environment, being fiscally responsible to consumer who bear all the operating and capital costs through water rates, and anticipating and avoiding unintended negative consequences. The Aqueduct has been working with their Wholesale Customer Board to navigate the challenges that face drinking water utilities in our modern world; microbial water quality issues, trace chemicals and emerging contaminants in the source water, and water quality issues resulting from treatment and distribution.

Chemicals are everywhere in our modern world. The technology used for chemical analysis has advanced to the point that it is possible to detect and quantify nearly any compound known to human kind down to less than a nanogram per liter or parts per trillion (1/1,000,000,000,000). This enhanced analytical ability has allowed scientists to discover that trace levels of pharmaceuticals, potential endocrine disrupting compounds (EDC) and other emerging contaminants exist in surface water, have appeared in some groundwater and may persist in the water through conventional and some advanced treatment trains to appear in our finished drinking water. The Washington Aqueduct and its partners on the Wholesale Customer Board and technical working group expert panel from consulting, academia, EPA and other Water Utilities are working to develop a framework to make decisions and chart courses of action when faced with these challenges. The first and continuing challenge is to keep evolving the understanding of what is the “best possible” drinking water and remember to consider all consequences before taking any action. The Washington Aqueduct of today is unlikely to be the first water treatment operation to make any change, but is unlikely to be surprised by unanticipated consequences of any changes in treatment that are made in the future. 

Thursday, December 20, 2012

EPA Announces Another New Air Standard

On Friday, December 14th in a conference called followed by a press release the U.S. Environmental Protection Agency, EPA, announced the reduction to the fine particle pollution, PM2.5, average annual allowed level to 12 micrograms per cubic meter (ug/m3) from 15 ug/m3. The EPA requires states to monitor air pollution to assess the healthfulness of air quality and ensure that they meet minimum air quality standards, and has some monitoring stations, but not all of the nation is monitored. The US EPA has established both annual and 24-hour PM2.5 air quality standards (as well as standards for other pollutants). The annual standard is now 12 ug/m3 (an AQI of 39). The 24-hr standard was recently revised to a level of 35 ug/m3 (an AQI of 99) and will remain unchanged. States will have until 2020 to meet the revised annual PM2.5 health standard. EPA projections show 99% of U.S. counties with monitoring stations will meet the standard with only 7 counties in California failing to meet the Annual Fine Particle Health Standard of 12 μg/m3. For coarse particles, PM10, EPA is retaining the existing 24-hour standard at 150 μg/m3 the same standard that has been in place since 1987.

Particulate matter is made up of particles that are emitted directly, such as soot and dust, as well as secondary particles that are formed in the atmosphere from reactions of precursor pollutants such as oxides of nitrogen (NOx), sulfur oxides (SOx), volatile organic compounds (VOCs), and ammonia (NH3). Particle are either directly emitted or formed in the atmosphere. Directly-emitted particles come from a variety of sources such as cars, trucks, buses, industrial facilities, power plants, construction sites, tilled fields, unpaved roads, stone crushing, and burning of wood. Other particles are formed indirectly when gases produced by fossil fuel combustion react with sunlight and water vapor. Many combustion sources, such as motor vehicles, power plants, and refineries both emit particles directly and emit precursor pollutants that form secondary particulates. Ammonium nitrate and ammonium sulfate are the principal components of secondary particulates. 

Particulate matter has immediate health impacts: itchy, watery eyes, increased respiratory symptoms such as irritation of the airways, coughing or difficulty breathing and aggravated asthma. Health effects can result from both short-term and long-term exposure to particulate pollution. Exposure to particles can also trigger heart attacks and cause premature death in people with pre-existing cardiac or respiratory disease. People most sensitive to particulate pollution include infants and children, the elderly, and persons with existing heart and lung disease. The particles can travel deep into the lungs, enter the bloodstream, and penetrate into cells. Smaller particles can penetrate deepest, causing the greatest harm. Researchers are still trying to identify which types and sources of particles are most hazardous to human health. Though, particles created from combustion soot tend to be fine particles with diameters smaller than 2.5 microns (PM 2.5) which are the most dangerous because it lodges in the lungs. Dust is mostly coarser particles. 

Since most counties will be in compliance with the new standard based on previous EPA regulations and auto emission standards, EPA estimates that meeting the annual fine particle standard of 12.0 μg/m3 will cost only between $53 million to $350 million, but provide health benefits worth an estimated $4 billion to $9.1 billion per year in 2020. If you would like to read about how these assessments are made see section 5 of “Regulatory Impact Analysis for theFinal Revisions to the National Ambient Air Quality Standards for ParticulateMatter” it is a window into the art and science of projecting benefits. 

Currently, EPA reports that there are 66 counties of the 569 that are monitored in the nation that do not meet the 12 ug/m3 annual standard. You might want to look to see if you live in one on this list, but not every county is monitored. Prince William is not, but Fairfax is. The new PM2.5 standard is the last in a long list of regulations to improve air quality in the United States and have resulted in even the seven worst counties in the country (all in California) having significantly better air quality than the PM2.5 air monitor atop the US Embassy in Beijing reports. Below is the list of air quality rules that have resulted in the tremendous improvement in air quality from 2000-2010 in the chart above and bring the United States to the next level in clean air. 

·        Light-Duty Vehicle Tier 2 Rule (U.S. EPA, 1999)
·        Heavy Duty Diesel Rule (U.S. EPA, 2000)
·        Clean Air Nonroad Diesel Rule (U.S. EPA, 2004)
·        Regional Haze Regulations and Guidelines for Best Available Retrofit Technology Determinations (U.S. EPA, 2005b)
·        NOx Emission Standard for New Commercial Aircraft Engines (U.S. EPA, 2005)
·        Emissions Standards for Locomotives and Marine Compression-Ignition Engines (U.S. EPA, 2008)
·        Control of Emissions for Nonroad Spark Ignition Engines and Equipment (U.S. EPA, 2008)
·        C3 Oceangoing Vessels (U.S. EPA, 2010)
·        Hospital/Medical/Infectious Waste Incinerators: New Source Performance Standards and Emission Guidelines: Final Rule Amendments (U.S. EPA, 2009)
·        Reciprocating Internal Combustion Engines (RICE) NESHAPs (U.S. EPA, 2010)
·        Mercury and Air Toxics Standards (U.S. EPA, 2011)
·        Cross-State Air Pollution Rule (U.S. EPA, 2011)

Monday, December 17, 2012

EPA approves DC Water’s Green Infrastructure Plan

Image from DC Water: GI= green infrastructure, CSO= combined sewer overflow

On Friday, December 14, 2012, the US Environmental Protection Agency officially announced its support for District of Columbia Water and Sewer Authority, DC Water's, proposal to extend the deadlines in the Consent Decree with the United States in order for them to test green infrastructure (GI) alternatives to its Clean River Project, its long term plan to control overflows for the District’s combined sewer system. Currently, the Clean Rivers Project is a $2.6 billion system of tunnels and diversion sewers for the capture of stormwater to prevent overflows to Rock Creek and the Anacostia and Potomac rivers and storage for later treatment at DC Water’s Blue Plains Advanced Wastewater Treatment Plant.

The EPA has announced its support of the modification of the consent decree so that DC Water may construct Green Infrastructure Demonstration projects. These projects will be used to evaluate (over the next 8 years) the effectiveness of green infrastructure to reduce stormwater runoff using techniques that mimic natural control measures to meet water quality goals under the National Pollutant Discharge Elimination System, NPDES, permit . If successful, these techniques could be used to help address the combined sewer overflow problems in the District, potentially reducing costs and/or improving control of stormwater overflows. As part of the agreement with EPA, DC Water will proceed with preparation of the Environmental Impact Statements required for the Potomac Storage Tunnel while the GI Demonstration Project and Alternatives Analysis are underway and as indicated above the Anacostia Tunnel projects will proceed on schedule.

District of Columbia's sewage system is one of the oldest in the United States and the combined storm water and waste water flows in the oldest section of the system have created a pollution problem whenever it rains. The combined volume of rainwater and sewage is too much for the Blue Plaines Advanced Wastewater Treatment Plant to process, so DC Water releases the excess rainwater mixed with untreated sewage to the Anacostia River, Potomac River and Rock Creek to prevent the sewage from backing up in homes and businesses and the Capitol. The sewage flow released in this way has violated the National Pollutant Discharge Elimination System, NPDES, permit which is how EPA regulates sewage treatment plants. The history of Washington DC’s NPDES permit and allowed outflows can be read here.

The BluePlains Advanced Wastewater Treatment Plant is located on the southernmost tip of Washington DC, across the river from Alexandria. Blue Plains sits on 150 acres of land and has a rated annual average day capacity if 370 million gallons per day (mgd) and a peak wet weather capacity of 1,076 mgd. The system needs a larger storm rated capacity to accommodate the old central city section which accounts for one third the area of the District and still has the old combined sewer system that overflows with predictable regularity during rain storms. DC Water is under a consent order from the EPA and the Department of Justice to meet new effluent limits for total nitrogen released and better control of the system during storms. To comply with the consent order DC Water developed the $2.6 billion Clean Rivers Project.

The Clean Rivers project was amended in 2007 to include the construction of Enhanced nitrogen removal, ENR, facilities for additional $950 million. The new ENR facilities will have the capacity to provide complete treatment for flow rates up 555 million gallons per day for the first 4 hours, 511 million gallons per day for the next 24 hours and at a rate of 450 mgd. When all the Clean River Project and ENR facilities components were completed, the Blue Plains Advanced Waste Water Treatment Plant is projected to be able to meet the nitrogen release standard under the NPDES operating permit, reduce the number of uncontrolled storm related releases of waste, but still not meet the Chesapeake Bay TMDL.  Buried in Appendix B of the Watershed Implementation Plan II, WIP II, for Washington DC is the fact that they cannot meet the EPA mandated TMDL for the Chesapeake Bay for the combined sewer system and Blue Plains Waste Water Treatment plant with the existing programs. More needs to be done.

In addition, seven years into the Clean Rivers Project, DC Water is facing the reality of the rate increases necessary to support the combined costs of the projects that will still not meet the TMDL. Building the 13-mile network of 23-foot-diameter tunnels to carry combined storm runoff and sanitary sewage to the Blue Plains Advanced Wastewater Treatment Plant for treatment rather than releasing untreated sewage and stormwater runoff to the rivers and creeks during heavy rainstorms is incredibly expensive and still may not be enough to solve the problem. So far the more than $600 million that has been spent for the Clean Rivers Project for in engineering preliminary work address mostly the Anacostia River Tunnel (which is really an interconnected series of three tunnels). According to Alan Hayman of DC Water, the Anacostia Tunnels will cost about $1.6 billion when completed and will have the greatest reduction in overflow releases. DC water is hopeful that the green infrastructure will allow downsizing of Potomac and Rock Creek tunnels (delay sewer rate increases) and ensure that DC Water ends up compliant with the NPDES permit, consent decree and the Chesapeake Bay TMDL. Green Infrastructure, if successful, can continue to grow and expand in effectiveness as these practices become commonplace and accepted.  
from DC Water 

Thursday, December 13, 2012

Sediment Disposal from the Washington Aqueduct Water Treatment Plants

Drinking water systems may obtain their water supply either directly from the rivers, lakes, reservoirs for surface water or from wells for ground water or like DC Water, Arlington and Falls Church may purchase finished water from wholesalers like the Washington Aqueduct. Raw water is treated to produce finished drinking water. During the treatment of source water, water treatment plants, WTPs, remove contaminants by screening, sedimentation, flocculation and filtration. The waste streams generated from these steps are water treatment residuals. In a 2011 report the US Environmental Protection Agency, EPA, estimated that approximately 31% of the WTPs directly discharge to surface water, 7% transfer residuals to waste water treatment plants and the remainder is disposed of on land.

Solid residuals from water treatment plants include sludge, schmutzdecke (biological surface layer in slow sand filtration units), and spent treatment media. Residuals contain contaminants removed from the source water and treatment chemicals added by the WTP. Prior to final disposal residuals from the source water treatment operations can be treated on site by the WTP. Washington Aqueduct has a newly constructed residuals management facility that disposes of the solids by contract hauling.  The residuals from the Aqueduct are being used for reclamation and backfilling under a Maryland surface mining permit. The residuals are permitted to be used  offsite as clean fill. The volume and characteristics of the residuals depend on the source water, drinking water production rate, efficiency of source water treatment, and type of source water treatment used. The goal of all residuals treatment/ solids removal systems is to decrease the volume of water while increasing solids content. This process creates two waste streams the liquid and the solid.

EPA’s Filter Backwash Recycle Rule, FBRR, established requirements to ensure that WTPs do not compromise the quality of finished drinking water when recycling water from residuals management. The FBRR requires WTPs that reuse certain wastewater liquid residuals (filter backwash, thickener supernatant, and dewatering process liquids) the water must be returned to a point in the water treatment process where it will be treated by coagulation and filtration.

Water treatment residuals solids contain naturally occurring suspended and dissolved solids from the source water, as well as precipitated solids generated by chemical treatment as well as residual contaminants from chemical treatment. The naturally occurring solids include sediment and soils that are carried to the Potomac in run off from rain and snow melt. These solids are regulated under the Resource Conservation and Recovery Act, RCRA, regulations and are classified as hazardous or nonhazardous. A waste is characterized as hazardous or nonhazardous based on its ignitability, corrosivity, reactivity, and toxicity. Generally speaking, these wastes are not toxic and are often sold and used as soil amendments in agriculture or disposed of by contract hauling to a permitted disposal facility. The solids residual from water treatment generally contains the river sediment, traces of the algaecides and flocculants.

Sludge generated by water treatment plants is not subject to regulation under the Biosolids Rule. The Biosolids Rule (part of the Clean Water Act Amendments of 1987) was created to protect public health and the environment from any anticipated effects from recycling of sewage sludge Biosolids. The toxicity of solid residuals from sewage treatment is assessed by the Toxicity Characteristic Leaching Procedure (TCLP), which is a soil sample extraction method for chemical analysis. If contaminant concentrations in the TCLP leachate are below those listed in the Land Disposal Restrictions of RCRA, the solid residual is classified as non-hazardous and can be disposed at a municipal landfill or other location. There is tremendous controversy associated with potential impacts of Biosolids and the land disposal or reuse of Class B and even Class A Biosolids. I am not aware of any controversy associated with agricultural use of solids residual (predominately river silt) of water treatment plants.

Monday, December 10, 2012

The Dalecarlia Reservoir and Water Treatment Plant

from Army Corps of Engineers via Wikimedia

I went up to the Dalecarlia Reservoir and Water Treatment Plant on MacArthur Boulevard for a tour and to speak with Thomas Jocobus, the General Manager. The Dalecarlia operations are the main location for the Washington Aqueduct. The Washington Aqueduct consists of the Dalecarlia Reservoir and Water Treatment Plant, the Georgetown Reservoir, and the McMillan Reservoir and Water Treatment Plant. The Washington Aqueduct draws water from the Potomac River and treats it to provide finished drinking water to the water distribution companies that buy water from them.

The Washington Aqueduct is a federally owned and operated by the Army Corp of Engineers and Mr. Jacobus like all employees of the Washington Aqueduct is a civilian employee of the Army Corp of Engineers. The Aqueduct was initially built with federal funds, but since 1927 the operating budget and capital budget have been paid for by the Aqueduct’s customers. Today, the operating budget is around $46 million that is supplied by the wholesale water rates charged for the water delivered. The Aqueduct produces an average of 155 million gallons of water per day and sells that water to the District of Columbia (about 75% of the finished water), Arlington County, Virginia (about 15%), and the City of Falls Church, Virginia (10%). In total about one million people a day use water supplied by the Aqueduct.

The maximum capacity of the Aqueduct is 320 million gallons of water per day much more than even the peak demand for drinking water and fire fighting for their customers. Though water use peaked at an average of 180 million of gallons a day about a decade ago, the system was expanded in the 1950’s anticipating serving Montgomery and Prince George counties, but the Washington Suburban Sanitary Commission (WSSC) instead built what is today the WSSC's principal water supply facility, the Potomac River Filtration Plant in western Montgomery County to supply their needs.

The Washington Aqueduct dates back to 1853 when congress appropriated $5,000 to develop the first portion of the system. The first portions of the system were the Dalecarlia Reservoir and Georgetown distribution reservoir. That portion of the system was designed to run on gravity, so that the system did not require pumps until much later when the system and the city expanded and demand for water required the expansion of the system. Even today the energy used is reduced because of the utilization of natural elevations in the design of the system. The Aqueduct first began delivering water in 1862. The Lydecker Tunnel and McMillian Reservoir and water treatment plant were added in 1905. The McMillian slow sand water treatment plant was the first treatment plant in the system and was built to address the increasing outbreaks of typhoid fever that were caused by contaminated drinking water. This was followed by a rapid sand filtration system at Dalecarlia to address the continued population growth after World War I.

Today the water for the Washington Aqueduct continues to be drawn from the Potomac River at the Great Falls and Little Falls intakes. This duel intake location about 10 miles apart allows for some degree of management of the water quality at intake if there should be a fuel spill or other water quality disturbance. On its way from the river intakes to the Dalecarlia reservoir, raw water passes through a series of screens designed to remove debris such as twigs and leaves and whatever trash finds its way into the Potomac River. Then copper sulfate and sodium permanganate are added as algaecides. All water drawn for the system enters the Dalecarlia Reservoir. While the water moves slowly through Dalecarlia Reservoir, much of the sand and silt settles to the bottom. This is called pre-sedimentation. After screening, the addition of the algaecides and pre-sedimentation the water is either pumped to the Dalecarlia or McMillan treatment plants.

The treatment plants filter and disinfect water from the Potomac River to meet safe drinking water standards. The treatment process is not identical at both plant, but it is very similar and includes sedimentation, filtration, fluoridation, pH adjustment, primary disinfection using sodium hypochlorite, secondary disinfection with chloramine through the addition of ammonia, and corrosion control with orthophosphate.
From the Army Corp of Engineers
The raw water from the Potomac River contains suspended solids, sediment, bacteria, and microorganisms that must be removed to produce finished drinking water. These are removed by the water treatment processes of the Washington Aqueduct after the initial screening and pre-sedimentation water treatment consists of:

Coagulation - A coagulant, aluminum sulfate (alum) and powdered activated carbon, is added to the water as it flows to sedimentation basins. Coagulants aid in the removal of suspended particles by causing them to consolidate and settle. Alum contains positively charged atoms called ions which attract the negatively charged particles suspended in water causing them to gather into clumps of particles heavy enough to settle. The activated carbon controls odor in the water.
Flocculation – The water is gently stirred with large paddles to distribute the coagulant; this causes particles to combine and grow large and heavy enough to settle. This process takes approximately 25 minutes. Cationic polymer and nonionic polymer are added.
Sedimentation – The water flows into quiet sedimentation basins where the flocculated particles settle to the bottom. After about four hours, approximately 85% of the suspended material settles out. Until recently, the sediment recovered was returned to the river, now the sediment residuals are collected from Dalecarlia, McMillan and Georgetown locations and then pumped to a central processing facility at Dalecarlia.  Residuals processing, including gravity thickening and dewatering, occur at the newly constructed Residual Management building. Following processing, trucks haul the residuals off-site to permitted land-disposal areas.
Filtration – Water at the top of the basins flows to large gravity filters, where the water flows down through filter media consisting of layers of small pieces of hard coal (anthracite), sand, and gravel placed in the bottom of deep, concrete-walled boxes. Filtered water passes through to a collecting system underneath. The filters are back washed every four days.
Disinfection – Chlorine in the form of sodium hypochlorite is added with precision equipment to kill pathogenic microscopic life such as bacteria or viruses. Ammonia is then added. The chlorine and ammonia combine to form chloramine compounds. This is the most recent significant change in the water treatment process and was required by changes in the Safe Drinking Water Act in the 1990's. The concentration of chloramines in the water is closely monitored from the time it is added at the treatment plants to points near the furthest reaches of the distribution systems.

The Dalecarlia operation has an EPA certified laboratory to perform the tens of thousands of analysis required each year under the Safe Drinking Water Act. One of the coolest features of the tour was seeing the surveillance of the water treatment train. In one of the laboratories is a trough sink with 15 spigots continually running. Each spigot continually draws water from one step in the treatment process. If a problem arises water at every point can be checked to make adjustments.

Fluoride, in the form of hydrofluorosilicic acid, is added to the finished water to reduce tooth decay; this is especially beneficial for children. Orthophosphate is added to control corrosion in pipes, service lines, and household plumbing throughout the distribution system. It works by building up a thin film of insoluble material in lead, copper, and iron pipes and fixtures. This thin film acts a barrier to prevent leaching of metals into the water. Calcium hydroxide (lime) is also added to adjust the pH of the water to ensure optimal performance of the orthophosphate.

After the water has completed its path through the treatment process, it is referred to as finished water and meets all requirements under the Safe Drinking Water Act. Because the Washington Aqueduct is in Washington D.C. it is directly regulated by the US EPA Region 3 office. The Washington DC regulators do not have primacy. Unlike most large urban water systems the Aqueduct does not have state regulators to answer to and its customers are the three water distribution systems DC Water, Arlington and Falls Church section of Fairfax County. Falls Church has come to an agreement to turn over their distribution system to Fairfax Water who will continue to buy water for that portion of the system from the Aqueduct. The Washington Aqueduct does not currently engage in any advanced water treatment, but is studying the options.  

Thursday, December 6, 2012

Interpreting Water Test Results

The Virginia Cooperative Extension (VCE) Offices in Virginia occasionally holds drinking water clinics for well, spring and cistern owners as part of the Virginia Household Water Quality Program. The VCE subsidizes the analysis cost for these clinics. Currently, samples are analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria at a cost of $49 to the well owner. This is far from an exhaustive list of potential contaminants, but with one or two exceptions these are the most common contaminants that effect drinking water wells. These are mostly the naturally occurring contaminants and common sources of contamination: a poorly sealed well or a nearby leaking septic system, or indications of plumbing system corrosion.

There are other contaminants that can be found in ground water in certain regions that can cause illness when exposed to small amounts over long periods of time Uranium is an example. There are also nuisance contaminants for which there is not an approved EPA methodology, iron bacteria is an example. A through water analysis should be performed before any treatment is considered to make sure the selected treatment is necessary and appropriate. Wells should be tested annually for bacteria and every 1-3 years for other common contaminants especially if you install treatment systems. Groundwater is dynamic and can change over time, and it is important to make sure that any treatment is still appropriate and effective.  Water treatment systems are not an install and forget piece of equipment, they are more systems to maintain, adjust and control to keep the water within ideal parameters. Improperly treated water can be as problematic as not treating water.
In order to determine if treatment is necessary, water test results should be compared to a standard. The standard we use if the U.S.EPA Safe Drinking Water Act in the list to the left. There are primary and secondary drinking water standards. Primary standards are ones that can impact health and from the list above include: coliform bacteria, E. coli and fecal coliform bacteria, nitrate, lead, and arsenic. Groundwater can sometimes be contaminate from nearby or historic land use. Before a home is purchased a much more comprehensive water analysis should be performed to ensure that groundwater is not contaminated with hydrocarbons, solvents, fuels, heavy metals, pesticides.

Coliform bacteria are not a health threat itself, it is used to indicate other bacteria that may be present and identify that a well is not properly sealed from surface bacteria. The federal standard for coliform bacteria is zero, but the federal standard allows that up to 5% of samples can test positive for coliform during a month. New coliform standards are anticipated to be promulgated shortly. Fecal coliform and E. coli are bacteria whose presence indicates that the water is contaminated with human or animal wastes. Disease-causing microbes (pathogens) in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. These pathogens may pose a special health risk for infants, young children, and those with compromised immune systems. However, people can drink water contaminated with fecal bacteria and not notice. If your water is contaminated with coliform but not fecal coliform or E. coli, then you have a nuisance bacteria problem and the source may be infiltration from the surface from rain or snow melt. Typical causes are improperly sealed well cap, failed grouting or surface drainage to the well. Shock chlorinate the well, repack the soil around the well pipe to flow away from the well and replace the well cap. Then after the next big rainstorm retest the well for coliform. If it is still present then a long-term treatment should be implemented:  using UV light, ozonation, or chlorine for continuous disinfection.

If you have fecal coliform in the well or E. coli, your well is being impacted by human or animal waste. If there is not a nearby animal waste composting facility, then you are probably drinking water from a failed septic system- yours or your nearest neighbors. To solve this problem you need to either fix or replace the septic system that is causing the contamination or replace the well. The failing septic systems can often be identified by using tracer dyes.  While continuous disinfection will work to protect you from fecal bacteria and E. coli, be aware that if your well is being impacted by a septic system, then the well water might also have present traces of all the chemicals and substances that get poured down the drain. Long term treatment for disinfection, and micro-filtration should be implemented:  using UV light, ozonation, or chlorine for continuous disinfection, carbon filtration, and anything that is used for drinking should be further treated with a reverse osmosis systems or micro membrane system that work by using pressure to force water through a semi-permeable membrane. This is the type of system that is used to desalinate water. Large quantities of wastewater are produced by reverse osmosis systems and need to bypass the septic system or they will overwhelm that system creating more groundwater problems. Reverse osmosis systems produce water very slowly, a pressurized storage tank and special faucet needs to be installed so that water is available to meet the demand for drinking and cooking.

 Nitrate can contaminate well water from fertilizer use; leaking from septic tanks, sewage and erosion of natural deposits. The MCL for nitrate is 10 mg/L. Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill from blue-baby syndrome and, if untreated, may die. Symptoms include shortness of breath and a blue ting to the skin common in blue-baby syndrome. The NO3 dissolves and moves easily through soil which varies seasonally and  over time as plants use up the nitrate over the summer. Testing in the spring will usually produce the highest levels. Nitrate may indicate contamination from septic tanks, but do not boil the water- boiling water reduces the water and actually INCREASES the concentration of nitrates. So if your water is being impacted by a septic system and you do not replace the well; distillation, reverse osmosis, or ion exchange is necessary to control the nitrate.

The EPA guidance for sulfate is 250 ppm for taste. Sulfates can clog plumbing and stain clothing and excessive levels can have a laxative effect. If you have hydrogen sulfate above 0.5 ppm you can probably smell the rotten egg smell in your water especially when the water is heated. Hydrogen sulfide naturally occurs in shale, sandstone, and near coal or oil fields. Sulfate and hydrogen sulfide are not regulated by the EPA for drinking water, they are a secondary contaminant and though extremely unpleasant, harmless to animals, but not to plumbing equipment. There is a related problem (for which there are limited methods of testing) of sulfur reducing bacteria. According to the EPA, sulfur-reducing bacteria and sulfur-oxidizing bacteria pose no known health risks. Sulfur-reducing bacteria live in oxygen-deficient environments such as deep wells, plumbing systems, water softeners, and water heaters. These bacteria usually flourish in hot water tanks and pipes. Sulfate reduction can occur over a wide range of pH, pressure, temperature, and salinity conditions and produce the rotten egg smell and the blackening of water and sediment by iron sulfide. Sulfate-reducing bacteria can cause the corrosion of iron in pipes and water systems.

The treatment method selected depends on many factors including the level of sulfate in the water, the amount of iron and manganese in the water, and if bacterial contamination also must be treated. High concentrations of dissolved hydrogen sulfide also can foul the resin bed of an ion exchange water softener. When a hydrogen sulfide odor occurs in treated water (softened or filtered) and no hydrogen sulfide is detected in the non-treated water, it usually indicates the presence of some form of sulfate-reducing bacteria in the system. Water softeners provide an environment for these bacteria to grow. “salt-loving” bacteria, that use sulfates as an energy source, may produce a black slime inside water softeners. If you have modest sulfate, but no rotten egg smell, installing a water softening system may create additional problems, especially if the system is not meticulously maintained. If you have a rotten egg smell associated with the hot water and elevated levels of sulfate on the cold water side, your hot water tank may be fouled with sulfur reducing bacteria, or the tank’s corrosion control rod may be causing the sulfur to react in the heated environment. 

Iron and manganese are naturally occurring elements commonly found in groundwater in this part of the country. At naturally occurring levels iron and manganese do not present a health hazard. However, their presence in well water can cause unpleasant taste, staining and accumulation of mineral solids that can clog water treatment equipment and plumbing.  The standard Secondary Maximum Contaminant Level (SMCL) for iron is 0.3 milligrams per liter (mg/L or ppm) and 0.05 mg/L for manganese. This level of iron and manganese are easily detected by taste, smell or appearance. In addition, some types of bacteria react with soluble forms of iron and manganese and form persistent bacterial contamination in a well, water system and any treatment systems. These organisms change the iron and manganese from a soluble form into a less soluble form, thus causing precipitation and accumulation of black or reddish brown gelatinous material (slime). Masses of mucous, iron, and/or manganese can clog plumbing and water treatment equipment. 

All systems of removing iron and manganese essentially involve oxidation of the soluble form or killing and removal of the iron bacteria.  When the total combined iron and manganese concentration is less than 15 mg/l, an oxidizing filter is the recommended solution. An oxidizing filter supplies oxygen to convert ferrous iron into a solid form which can be filtered out of the water. Higher concentrations of iron and manganese can be treated with an aeration and filtration system. This system is not effective on water with iron/ manganese bacteria, but is very effective on soluble iron and manganese. Chemical oxidation can be used to remove high levels of dissolved or oxidized iron and manganese as well as treat the presence of iron/manganese (or even sulfur) bacteria. The system consists of a small pump that puts an oxidizing agent into the water before the pressure tank. The water will need about 20 minutes for oxidation to take place so treating before a holding tank or pressure tank is a must. After the solid particles have formed the water is filtered. The best oxidizing agents are chlorine or hydrogen peroxide. If chlorine is used, an activated carbon filter is often used to finish the water and remove the chlorine taste. The holding tank or pressure tank will have to be cleaned regularly to remove any settled particles.

Fluoride occurs naturally in groundwater and in certain parts of Eastern Virginia there are very high naturally occurring levels. Fluoride is a primary water contaminant and the EPA MCL 4.0 mg/L and SMCL 2.0 mg/L. Fluoride is typically added in small quantities to public water supplies the optimum concentrations for public systems 0.8 - 1.2 mg/L. Excessive levels of fluoride can cause fluorosis or bone cancer over long term exposure. Treatment for excessive levels of fluoride in water is typically reverse osmosis which will remove all fluoride and minerals from water.

The pH of water is a measure of the acidity or alkalinity. The pH is a logarithmic scale from 0 – 14 with 1 being very acidic and 14 very alkaline. Drinking water should be between 6.5 and 7.5. For reference and to put this into perspective, coffee has a pH of around 5 and salt water has a pH of around 9. Corrosive water, sometimes also called aggressive water is typically water with a low pH. (Alkaline water can also be corrosive.) Low pH water can corrode metal plumbing fixtures causing lead and copper to leach into the water and causing pitting and leaks in the plumbing system. The presence of lead or copper in water is most commonly leaching from the plumbing system rather than the groundwater. Acidic water is easily treated using an acid neutralizing filter. Typically these neutralizing filters use a granular marble, calcium carbonate or lime. If the water is very acidic a mixing tank using soda ash, sodium carbonate or sodium hydroxide can be used. The acid neutralizing filters will increase the hardness of the water because of the addition of calcium carbonate. The sodium based systems will increase the salt content in the water.

Water that contains high levels of dissolved minerals is commonly referred to as hard. Groundwater very slowly wears away at the rocks and minerals picking up small amounts of calcium and magnesium ions. Water containing approximately 125 mg/L can begin to have a noticeable impact and is considered hard. Concentration above 180 mg/L are considered very hard. As the mineral level climbs, bath soap combines with the minerals and forms a pasty scum that accumulates on bathtubs and sinks. You either must use more soap and detergent in washing or use specially formulated hard water soap solutions. Hard water can be just a minor annoyance with spotting and the buildup of lime scale, but once water reaches the very hard level 180 mg/L or 10.5 grains per gallon, it can become problematic. Hard water spots appear on everything that is washed in and around the home from dishes and silverware to the floor tiles and cars. When heated calcium carbonate and magnesium carbonate are removed from the water and form a scale (lime scale) in cookware, hot water pipes, and water heaters.

Water softening systems are used to address the problem are basically an ion exchange system. The water softening system consists of a mineral tank and a brine tank. The water supply pipe is connected to the mineral tank so that water coming into the house must pass through the tank before it can be used. The mineral tank holds small beads of resin that have a negative electrical charge. The calcium and magnesium ions are positively charged and are attracted to the negatively charged beads. This attraction makes the minerals stick to the beads as the hard water passes through the mineral tank. Sodium is often used to charge the resin beads. As the water is softened, the sodium ions are replaced and small quantities of sodium are released into the softened water, thus the salty taste of softened water. When the water softening system is recharged the excess sodium solution carrying the calcium and magnesium is flushed to the septic system which may shorten the life of the drain field.

 At the present time the EPA guidance level for sodium in drinking water is 20 mg/L. This level was developed for those restricted to a total sodium intake of 500 mg/day and does not necessarily represent a necessary level for the rest of the population. Based on taste of the water levels of sodium should be below 30 to 60 mg/L based on individual taste. Water softening systems add sodium. Reverse osmosis systems and distillation systems remove sodium and are safe for household use, but addressing hard water by using vinegar to descale pots and dishwashers, regularly draining hot water heaters, and using detergents formulated for hard water might be a better solution for you.

Arsenic is not a common contaminant in groundwater that has not been impacted from surface runoff. Arsenic can be caused by erosion of natural deposits, but is more typically caused by runoff from orchards, runoff from glass & electronics production wastes, or leaching from coal ash disposal of or  agricultural chemical mixing areas.  The EPA standard for arsenic is 0.01 mg/L. Arsenic removal depends on the type of arsenic (there are two types) and the other contaminants present in water. Arsenic removal methods or systems include anion exchange, reverse osmosis, activated alumina, and other types of adsorptive media filters. Each method has its limitations, advantages and disadvantages and should be chosen based on additional analysis.  

Monday, December 3, 2012

More Climate Talks, But It's Too Late

The United Nations Framework Convention on Climate Change meeting in Doha, Qatar to once more discuss, negotiate and talk about climate change has reached the halfway point. Concerns crystallized by the recent damage from Hurricane Sandy have resulted in 17,000 attending the conference, but that is the only good news. The goal of all these meetings is to negotiate a new agreement by 2015 that will become effective by 2020 to replace and expand the Kyoto Protocol. If an agreement can be negotiated, and this is a big if, it will extend CO2 mitigation requirements to all countries, both developed and developing. Environmental activists and climate scientists, the Alliance of Small Island States, the Africa Group and the Least Developed Countries group are all calling for deeper carbon cuts now to avert climate impacts. However, if the climate models are correct, it's too late. The die is cast.  Though many nations had pledged to keep global warming from exceeding two degrees Celsius, according to the climate models the CO2 emissions trend will produce between 3 and 5 degree Celsius increase in global temperatures and we should be planning for the future we will have and hope for a better one.

According to the International Energy Agency, IEA, 2011 estimates of world CO2 emissions from fossil fuel combustion, World CO2 emissions rose by 1 billion metric tons in 2011, a 3.2 % increase  to reach 31.6 billion metric tons. In 2011 the top four world generators of CO2 emission from fossil fuels were in descending order China, the United States, the European Union and India who edged out Russia to take the number four slot. There is no short term action that will stop the CO2 concentrations from reaching the climate model project tipping point of 32.6 billion metric tons of CO2 emissions annually just 1 billion metric tons above current levels and the amount the world emissions increased last year.

China, the largest emitter of CO2 increased their emissions the most. China contributed almost three quarters of the global increase, with its emissions rising by 720 million metric tons, or 9.3% to 8.46 billion metric tons of CO2, primarily due to higher coal consumption. India’s emissions rose by 140 million metric tons or 8.7% to 1.75 billion metric tons. CO2 emissions in the United States in 2011 fell by 92 million metric tons of CO2 or 1.7% to an estimated 5.32 billion metric tons.  U.S. emissions have now fallen by 430 million metric tons or 7.7% since 2006, the largest reduction of all countries or regions. Unfortunately, this decrease has been made practically meaningless by the unrelenting growth in China and India.

China’s chief climate negotiator Xie Zhenhua recently announced that China’s CO2 emission would peak around 2030, pointing out that its per capita gross domestic product would have only reached half the level of other developed countries’ CO2 emissions when they peaked. No comment was made on the projected peak per capita CO2 emissions. In 2010 China surpassed the US in manufactured output, energy use and car sales. According to the International Monetary Fund, IMF, China will shortly be the world's largest economy. However, while the economy has been growing leaps and bounds, China's total fertility rate (the average number of children a woman has during her lifetime) has fallen to 1.56. The United Nations now projects that China’s population will peak in 2026. So after China’s population begins to decrease, they anticipate that their CO2 emission will peak. Yeah, I would project that, too-it is the natural course of events.  China’s delegate to the current conference,  Su Wei, indicated that they expect China and other developing countries to remain exempted from CO2 reduction requirements for the next treaty making the current discussion entirely pointless and changes the direction the negotiations should take. The world needs to develop plans to survive the bulge in CO2 emissions and any climate consequences from China's sprint to peak population and peak CO2 emissions.
From the Economist using UN data

Unlike the rest of the developed world, China's population control policy of one child will cause the nation to grow old before it grows rich. In 2010 8.2% of China's total population was over 65. The over 65 segment it is expected to grow to 26% by 2050. Right now China represents approximately 20% of the world's population. As their population ages and declines, CO2 emissions are expected to stabilize and decline. For comparison in the United States 13% of the population is over 65 and that is forecast to grow to 21% by 2050. U.S. CO2 emissions are falling and our nation is well on track to meet the President’s promise of reducing CO2 emissions 17% below 2005 levels by 2020. Though, the CO2 emissions per capita in the United States is still three times the level in China. As the population of the United States continues to grow, to  be able to grow GDP and reduce CO2 emissions would be a significant achievement. Unfortunately, this decrease will be made almost meaningless by the unrelenting growth in CO2 emissions in China and India. We have little leverage and no control over those nations and so the global CO2 levels will continue to grow until those nations peak. Possibly we should be planning for moving population centers away from the coastal estuaries to better survive rising oceans and increasing storm intensity. 
Chart from IEA 2012 publication