Sunday, December 31, 2023

Our Woodlands Need Our Help

a finished section 

I am embarking on the fifth year of my woodland restoration project. My house sits on a bit over 10 acres, about three of them lawn and ornamental gardens. The remaining seven acres is woodland, and much of the woodland is part of the “resource protected area,” RPA, of the Chesapeake Bay. 

When we first moved here we did not worry about dead trees, as it was all part of the natural process of renewal. A healthy forest has living trees functioning as part of a balanced and self replacing ecosystem that is a complex mix of trees, understory shrubs and groundcover. In a healthy woodland the process of natural succession occurs over time. Small saplings develop and will become the next generation of trees as the older ones die out. Benign neglect had been my rule for managing the RPA that protects the stream.  

However, about a decade ago, I noticed that something had gone seriously wrong with the forest. The woodland was being destroyed by invasive insects, invasive vines and an explosion of deer and wildlife consuming the native understory. Though I have seen them munch the kibble we put out for the cats dumped in our woods, deer prefer to eat native plants. They devour the saplings of the native  trees, but pretty much leave the autumn olive and other invasives alone. When a gap appears in the canopy, there aren’t young trees in the understory waiting for their chance to grow in the sun, but rather, invasive vines and shrubs waiting to take over the landscape.

The woodlands are necessary for a functioning ecology. RPA’s in the Chesapeake Bay Preservation Act are vegetated areas along water bodies, such as lakes, streams, rivers, marshes or shoreline. RPAs are the last line of defense for the protection of water quality. These buffers stabilize shorelines and stream banks, filter pollutants, reduce the volume of stormwater runoff and provide critical habitat for aquatic species and wildlife. Trees and shrubs in riparian buffers reduce erosion, improve air quality, and provide shade in the summer, windbreaks in the winter and even store carbon.

About a decade ago the number of dead and dying trees had increased dramatically due to the emerald ash borer and it became obvious that the invasive vines, autumn olive and Japanese honeysuckle were choking out the natural renewal process. So, with guidance from the Forest Service and the Chesapeake Bay Act guidelines I began a project to restore my woodlands.   

First I called the  Virginia Department of Forestry to ask for advice. I did not know at the time that Prince William County had its very own forester. An Urban and Community Forestry Specialist from the Virginia Department of Forestry came out and inspected the woodland and made some recommendations.  He felt that with removal of the invasive vines and the hanging dead trees the wood might begin to renew itself. He put his recommendations in a report for me to submit to Clay Morris, Natural Resources Section Chief, Environmental Services Division of Prince William County Public Works to approve the work in the the RPA. Though the RPA covers just 2/3 of the woodland, I am treating all the wooded area in the same way. My proposal to Prince William County was strictly by the book in what is allowed in an RPA.   

It is slow work and expensive. Every winter a small crew hand cuts the invasive vines and then comes back in the spring to paint the cut stems of the invasive vines with herbicide. We are now in the fifth winter of my RPA and forest restoration process and are really beginning to see progress. I use "we" very loosely, Wetland Studies and Solutions is doing all of the actual labor, my husband and I are simply paying them and directing the sections to be done.  Here are a few pictures of the progress. 

This first picture is a section of the woodland before work began to remove invasive vines and plants in this area two years ago. It shows the trees covered in invasive vines. The vines were killing what life remained. We began by cutting the largest sections down with a chainsaw.


 2 years ago before work to remove invasives

In this second picture two years later it shows almost the same view after two years of work cutting out sections of invasive vines, extinguishing them with herbicide so they will not reattach to the base, removing some sections and letting vines dies and fall from the trees. Much of the cut wood was moved to make a pathway a section of which is seen above. 

This picture gives you a view of a section where the vines were cut and left to wither and die. Excessive amounts of cut vines and old barbed wire were removed. 

Wednesday, December 27, 2023

The Carbon Budget is almost used up


The following is from the press release from Imperial College London and the Study cited below:

Lamboll, R.D., Nicholls, Z.R.J., Smith, C.J. et al. Assessing the size and uncertainty of remaining carbon budgets. Nat. Clim. Chang. 13, 1360–1367 (2023).

Researchers at Imperial College London recently published a study in Nature Climate Change, that is the most up-to-date and comprehensive analysis of the global carbon budget. The carbon budget is an estimate of the amount of carbon dioxide emissions that can be emitted while keeping global warming below certain temperature limits.

In 2015 196 countries adopted  the Paris Climate Accord that was intended to put the nations on a course to reduce carbon dioxide emissions from the combustion of fossil fuels. The agreement was signed on Earth Day 2016 at the United Nations. The signing was a very hopeful moment. The Paris Agreement aims to limit global temperature increase to well below 2°C above preindustrial levels and pursue efforts to limit it to 1.5°C. The remaining carbon budget is one commonly used way to assess global progress against these targets.

The researchers state that previous found that global temperature rise is not strongly dependent on when carbon emissions occur, only on what the emissions cumulative sum is. However, the remaining carbon budget is strongly dependent on both how much and when different types of non-CO2 greenhouse gas emissions occur.  Using two models to account for this, the Imperial College London study estimates that for a 50% chance of limiting warming to 1.5°C, there are less than 250 gigatonnes of carbon dioxide left in the global carbon budget.

from the GCP

The researchers warn that if carbon dioxide emissions remain at 2022 levels of about 40 gigatonnes per year, the carbon budget will be exhausted by 2029, committing the world to warming of 1.5°C above preindustrial levels. To remain within 2°C above preindustrial temperatures humans need to emit less than 500 gigatons of additional carbon dioxide. At the current rate of emissions that is 12 years. There is still room for action in the 2°C above preindustrial level remaining carbon budget for global action.

Earlier studies had found that if carbon dioxide emissions continue at current levels, the remaining carbon budget to keep the global temperature within  2°C of preindustrial levels would be exhausted by 2046. The new study tells us that date is now 2036.

The finding means the budget is less than previously calculated and has approximately halved since 2020 due to the continued increase of global greenhouse gas emissions, caused primarily from the burning of fossil fuels as well as an improved estimate of the cooling effect of aerosols lost due to measures to improve air quality and reduce emissions.

The planet is faced with a huge challenge. Even if every nation met their current  pledge to reduce carbon dioxide emissions made in the Paris Climate Accord and its updates, the reductions promised are not enough to even maintain global temperatures within 2 °C above pre-industrial levels; and the nations are not meeting those pledges. Neither China nor India representing about a 40% of world carbon dioxide  emissions have committed to any reductions. Instead, they are projecting when their greenhouse gas emissions will peak and that is in more than a decade.

Sunday, December 24, 2023

Deicing Aircraft and their Pollution Contributing to Dead Zones

 The following has been excerpted from the USGS study and press release:

Airport Deicers: An Unrecognized Source of Phosphorus Loading in Receiving Waters
Owen M. Stefaniak, Steven R. Corsi, Troy D. Rutter, and Greg G. Failey
Environmental Science & Technology 2023 57 (44), 17051-17060
DOI: 10.1021/acs.est.3c03417

As winter approaches and temperatures get colder, removing ice and snow and preventing ice formation from aircraft and runways becomes essential for safe air travel. My husband and I met in Washington DC in the 1970’s and were a young married couple when just minutes after takeoff when in January 1982 Air Florida Flight 90 to Florida crashed into the 14th Street bridge killing 78 people. The cause was inadequate deicing and pilot error in responding to the problem. Had we not left DC for my husband's graduate work, we would have likely been on that bridge commuting into the District. 

Airports use a variety of products to remove or prevent ice and snow. Commonly used aircraft deicer and anti-icing fluids (ADAF) to remove ice, and anti-icers for inhibiting the formation of new ice on the aircrft. Use of these deicing products is required by the Federal Aviation Administration after a series of disasters in the last decades of the 20th century. during periods of ice and snow accumulation on aircraft.

These deicing agents usually contain chemicals that can affect local ecosystems. Stormwater runoff from airports is regulated and managed by airports. “Monitoring ice control product runoff is an important part of an airport’s pollution prevention plan, and in many cases, these plans include monitoring of phosphorus runoff,” says USGS Physical Scientist Owen Stefaniak, lead author of the study, “But accounting for the true source of phosphorus observed in airport runoff can be a real challenge for airport managers. Since these products contain proprietary ingredients not disclosed by the manufacturers, the airlines have no way to know how much phosphorus they are applying when they deice a plane.”

The new USGS study found that nine of eleven ice control product formulations used at airports contained phosphorus. Airports often take measures to reduce runoff from ice control products during freezing precipitation periods. In the coldest climates deicing pads drain to recovery tanks. However, preventing all runoff from aircraft and runway deicing operations during inclement weather while maintaining flight schedules is not typically possible.

Phosphorus exists naturally in the environment, but high levels can drive overgrowth of algae and plants, depleting oxygen and causing harmful algal blooms, fish mortality and habitat loss what is called a dead zone and is typically seen in summers. USGS scientists collected water samples during the deicing season as well as during the warmer months over a period of five years to see if airport ice control products were contributing to phosphorus pollution in local waterways.

The extent of each year’s dead zone is dependent on several factors, including how much nitrogen and phosphorus pollution enters waterways. High precipitation can contribute to the dead zone because it leads to more polluted runoff washing into rivers and streams from agriculture. In the Chesapeake Bay watershed we have had several warm winters in a row as well as lower than average dead zones. Precipitation was below average for most of 2023 delivering less nutrient pollution especially during the critical spring season, but it is unknown what impact if any the warm winters have had. 

The study was conducted in the area around Mitchell International Airport in Milwaukee, Wis., but the deicing products examined are extensively used at airports that experience freezing conditions nationally. During deicing periods, USGS found that 84% of the samples that were collected downstream of the airport had phosphorus that could likely be traced to ice control products, and 70% of the water samples had phosphorus levels that exceeded the Wisconsin Department of Natural Resources phosphorus aquatic life guidelines for streams, indicating potential for harm to the aquatic ecosystems receiving airport runoff.

The study focused on estimating how much phosphorus might be entering the streams from the ice control products, but it is still unclear how phosphorous from this source affects local ecosystems or whether this phosphorus is in a form readily available to aquatic organisms. Ice control product applications occur during freezing weather and phosphorus may not have the same environmental impact as it would during warmer months, when plant and algae growth is much greater.

Wednesday, December 20, 2023

Be Ready to Prevent Pipes from Freezing

Virginia has a moderate four-season climate that is typically humid in summers with mild winters, but there is tremendous variation over the Commonwealth and from year to year. There are those dry years, warm years, and cold and snowy years. Because of the usually mild winters here in Virginia, we do not often think of frozen pipes until an artic frost has arrived or when it is too late, and the pipes are already frozen. I was reminded this morning when I finally turned off the hoses. 

When sub-zero weather is in the forecast, we need to prepare our homes to prevent our pipes from freezing. According to Consumer Reports “burst pipes are one of the most common causes of property damage during frigid weather and can cost you thousands to repair. The pipes most at risk are those in unheated interior spaces such as basements, attics, and garages.” In Virginia, it is common to find bathrooms built above garages, or pipes running through the garage or an attic dormer. If you have a bathroom above a garage keep a small ceramic electric heater ($40) in the garage connected to a thermocouple that turns it on when the temperature in the garage falls below 40 degrees Fahrenheit. Turn on the heating cube in the garage and check it functioning when you turn off the hoses in late fall.

The likely pipes to freeze are against exterior walls of the home, or are exposed to the cold, like outdoor hose bibs, and water supply pipes in unheated interior areas like basements and crawl spaces, attics, garages, or kitchen cabinets. Pipes that run against exterior walls that have little or no insulation are also subject to freezing. It is easier to prevent pipes from freezing than to unfreeze them.

When the weather is forecast to fall into the single digits or lower open kitchen and bathroom cabinet doors to allow warmer air to circulate around plumbing, especially if your sinks are on an exterior wall or against attic dormers, and in the most extreme weather run an extra ceramic electric heater overnight keeping that bathroom toasty while the rest of the house is at an energy saving 65 degrees.

In sub-zero weather wells with and without separate well houses can freeze. Keeping the temperature in a well house above freezing or your well pipe insulated can prevent this. It used to be easy, that inefficient 100-watt incandescent bulb gave off enough heat to do the job, but now with more efficient bulbs, insulation and another source of heat is needed. An electric blanket can do the job. Deep wells are unlikely to freeze, it is usually a supply line not buried deep enough. Abnormally cold snaps can identify a private well line that was not buried deep enough at its most vulnerable point where it connects to the foundation.

Letting the water run in very freezing weather can work; however, can also create other problems. While running water may prevent the water supply lines from freezing, in the coldest weather the slowly running water might cause the drainpipe to the septic system (if you have one) to freeze and block the flow or even burst, and it can overwhelm a septic system. If you are on public water and sewer letting water trickle can prevent frozen pipes. You will see a significant increase in your water usage (still cheaper than repairing the damage from a burst pipe).

Frozen pipes can happen in your supply line or other parts of the house. There are things you can do to prevent frozen pipes. A couple of ceramic electric heat cubes, thermocouple, electric blanket, and a little strategy can prevent frozen pipes if there is heat in the home. However, electric heat pumps are extremely common in Virginia and becoming more so as various climate related programs push to transition to all electric households.

If the power should go out during a freeze, there may be no way to prevent the pipes in the home from freezing. Turning off the water at the main may be your best option if the power goes out and you do not have a generator or backup gas heat. Battery backups can help keep essentials running.

Whatever you do, do not run a gas-powered generator in the house and be wary of propane heaters not meant for interior use. We have a shop propane heater designed for indoor use and comes with an oxygen depletion sensor. These sensors detect the oxygen level in the air and turn off the propane. We also have battery operated carbon monoxide (CO) monitors throughout the house.

CO is an odorless, colorless gas that can kill you. This silent killer shows up any time you burn fuel, and it can quickly take over a home. Symptoms of carbon monoxide poisoning may resemble the flu (vomiting, dizziness, headache). So, use the CO monitors.

Sunday, December 17, 2023

Decentralized Water Treatment

To explore ways to lower costs and technology hurdles to distributed water treatment systems, National Alliance for Water Innovation (NAWI) and Stanford’s Water in the West convened a meeting of experts in February 2023 at Stanford University. Their  report was recently released and cited below summarizes the findings of the workshop that brought together researchers, industry experts, practitioners, policymakers and other stakeholders to discuss the current state of knowledge in extreme decentralized water treatment systems, and to identify the areas where further research and development are needed to allow the spread of this practice. All the comments of this blog entry are derived from the report of the workshop cited below.

Fairhart, A., Sedlak, D.L., Fiske, P., Kehoe, P., and Mauter, M. (2023). Extreme Decentralized Water Treatment. Exploring the Future of Premise-scale Water Treatment and Reuse: A Water in the West Series. Available at:

Access to an adequate quantity of treated and piped potable water and management of wastewater produced in homes and businesses is expected by all city dwellers and most suburban dwellers in wealthy countries like ours. Readily available safe drinking water and treatment of sewage is also crucial to public health and protection of the environment. For well over a century, municipal drinking water provision and wastewater management have been made possible by large investments in centralized systems. Fresh water withdrawn from rivers, reservoirs, and groundwater passes through drinking water treatment plants and is distributed through a vast underground pipe network to buildings throughout our urban and suburban communities.

After it is used, wastewater is collected in underground sewers that carry it to wastewater treatment plants to be cleaned to regulatory requirements prior to its discharge to the environment. In some water-stressed cities and locations like Northern Virginia some of the treated wastewater undergoes additional treatment to be directly or indirectly reused. This recycled water often is returned to users through another dedicated water distribution system recycling of the purple pipe water (non-potable by convention) in Loudoun County for data centers or in Fairfax for golf courses and ball fields. Alternatively, treated wastewater may be subjected to advanced treatment prior to being returned to the drinking water supply like delivering treated UOSA wastewater to the Occoquan Reservoir via release into the Occoquan River.

Although water reuse via the purple pipe system solves problems, the costs associated with the construction of a dedicated water distribution system for non-potable water throughout an entire area has high relative costs, regulatory complexities, and risks of unintentional cross-connections between recycled water and potable water pipes have limited the spread of such systems. The second approach, direct recycling is hindered in many places by the “ick” factor, but in locations like Northern Virginia, utilizing the Occoquan River to deliver the treated wastewater to the Occoquan Reservoir overcomes that. Another alternative, a relatively new approach to water recycling called decentralized water reuse may have promising advantages for utilities, developers, data centers and entrepreneurs.

Distributed water recycling systems have made considerable progress in cities where there is a recognition of the need to address water scarcity due to climate and growth and where partnerships have been built between utilities, building operators and regulatory authorities. The current generation of treatment technologies for distributed treatment typically recycle less than half of the wastewater produced within the building. In part, this is due to concerns about costs, but it is also determined by constraints put upon uses of recycled water in buildings. Although it is technically feasible to treat wastewater to a point at which it can be used for drinking, cooking and bathing, or to employ rooftop rainwater collection for potable purposes, such projects have rarely been built due to concerns about safety or the acceptability of the water.

With data centers, the bulk of the on-site water demand is for non-potable uses- cooling and watering of landscape. In a water-cooled system, water-cooled chillers and cooling towers located on top of the data center roofs produce chilled water, which is delivered to computer room air conditioners for cooling the entire building. In 2021, when Prince William County looked at water consumption for its 25 operational data centers at the time it found that water use varied by season and ranged from about 0.2 to 0.5 gallons per square foot per day. Prince William County Board of County Supervisors have recently approved rezonings that will ultimately result in tens of millions of square feet of data centers. Utilizing on-site water treatment could reduce the need for expansions of the UOSA plant, address part of the growing salinity problem, and reduce the cost of treatment for Fairfax Water.  

The workgroup at Stanford found that although existing technologies have proven to be adequate for the current generation of distributed water recycling systems, there is considerable room for improvement. NAWI was founded to conduct research research to lower costs and improve the feasibility of technologies that could help make non-traditional water sources a larger part of our nation’s water portfolio. In Japan more than 2,500 individual buildings in the country utilize in-building wastewater reclamation and rainwater harvesting systems, an alternative approach to centralized treatment that creates sustainable, resilient structures (Kimura et al. 2013). These systems treat different types of wastewaters within each building, including domestic sewage and graywater. The treated water is then used for various purposes like toilet flushing, cooling, garden watering, car cleaning and even fire protection. The emphasis in Japan  is on reusing water within the building where it was generated.

The shift towards building-scale water management has been facilitated by various factors, such as supportive local regulations, favorable tax policies, and technological expertise in designing and operating these systems. Further, the availability of a design manual and clearly defined water quality requirements for reclaimed water have further bolstered the adoption of on-site wastewater reclamation.

This approach has not worked as well in Bengalaru, India. The adoption of building-scale water treatment has not been as successful, the city’s journey features a blend of policy directives, innovative industry response and consumer-centric approaches (Miƶrner et al. 2023). Small-scale sewage treatment plants (SSTPs) are mandated to be included in all new construction and certain existing buildings. These systems are often contained within the building complex, treating wastewater for reuse in non-potable applications, like gardening and toilet flushing, contributing to a circular water economy at the community level.

Bengalaru, India lacks governance structures and regulatory standards, and the city grapples with ensuring accountability and quality in the rapidly growing ONWS market. Furthermore, concerns surrounding the health and safety of workers interacting with these systems underline the urgency for comprehensive regulation. Bengaluru’s story is one of policy-induced innovation and adaptation in the face of necessity. It serves as a reminder that while solutions can be replicated, execution of the solution will vary based on a variety of factors.

The factors for success identified in the report, would favor a distributed reuse for data centers. The bulk of water used on site is for non-potable purposes, the waste water tends to be fairly uniform in characteristics and there is a localized tremendous volume. The conversion of natural landscapes to impervious surfaces creates a stormwater problem whose solution could provide makeup water to the recycled on-site water. Virginia needs to work with NAWI and the data center industry to address this opportunity for sustainable water use.   Amazon Web Services (AWS) and Goggle have  commited “to be water positive by 2030.” Let’s see if we can do something to make all the data centers in Northern Virginia sustainable.  

Wednesday, December 13, 2023

COP 28 Ends

The 2023 United Nations Climate Change Conference or Conference of the Parties of the UNFCCC, more commonly known as COP28 ended yesterday. Government ministers representing nearly 200 countries on Wednesday agreed to a deal that calls for a transition away from fossil fuels, after a previous proposal was met with heated and widespread backlash. The agreement reached at COP28 failed to commit to a full fossil fuel phase out as hoped by many. While a commitment to end the use of fossil fuels was not achieved in Dubai, the outcome marks the beginning of the transition away from fossil fuels.

The final agreement published by the UAE earlier on Wednesday, was agreed on after all-night discussions, called for a “transitioning away from fossil fuels in energy systems, in a just, orderly and equitable manner, accelerating action in this critical decade, so as to achieve net zero by 2050 in keeping with the science.”

The deal text also urged for “accelerating efforts towards the phase-down of unabated coal power” and for “tripling renewable energy capacity globally and doubling the global average annual rate of energy efficiency improvements by 2030.”

Critically, the proposal did not mandate an absolute phase-out of hydrocarbons. However, COP28 did triple renewable energy targets, double energy efficiency goals, establishing a Global Goal on Adaptation framework, and beginning the operations of the loss and damage fund.  This is progress, the first pledges from wealthy nations were made in Dubai to support the fund.  The final text retains the calls for a doubling in adaptation finance and plans for assessments and monitoring of adaptation needs in the coming years. 

In his closing address at COP28, UN Climate Change Executive Secretary Simon Stiell  stressed the need for faster progress to keep the 1.5-degree pathway viable. “Whilst we didn’t turn the page on the fossil fuel era in Dubai, this outcome is the beginning of the end,” said Mr. Stiell, who simultaneously acknowledged, “We’re currently headed for just under 3 degrees.  This still equates to mass human suffering, which is why COP28 needed to move the needle further. The global stocktake showed us clearly that progress is not fast enough, but undeniably it is gathering pace.” He further acknowledged the crucial role of ordinary people in driving climate action, and concluded by stating that UN Climate Change remains committed to supporting every step of the journey in the race to a sustainable future.

Sunday, December 10, 2023

Global Carbon Budget 2023

 The COP 28 meeting continues, but the news release last week from the Global Carbon Project is not good. Their report shows what a big lift it will be to meet the promises of the Paris Accord. 

The Global Carbon Project is an international research project and partner of the World Climate Research Programme. The Global Carbon Project aims to develop a complete picture (quite literally with incredible infographics) and integrates all the knowledge of greenhouse gases, human activities and the Earth system. They were founded in 2001 to fully understand the carbon cycle on our planet. Their projects include global budgets for the three dominant greenhouse gases (carbon dioxide, methane, and nitrous oxide) and track growth in and source of emissions, performance against the Paris Accord commitments and efforts in urban, regional, cumulative, and negative emissions. The just released  Global Carbon Budget 2023 is the source of the below comments.

The people at the Global Carbon Project found that CO2 emissions from fossil use are projected to rise 1.1% in 2023, reaching 36.8 billion tonnes of carbon dioxide (GtCO2).  Growth took place in all fuel types (coal, oil, natural gas). This brings fossil CO2 emissions to a record high 1.4% above the 2019 pre[1]COVID-19 levels.

While emissions are declining in 26 countries, these efforts remain insufficient to reverse the growth in global fossil fuel emissions in China and India. Growth in total CO2 emissions for our planet – the sum of fossil and land-use change emissions are projected to be 40.9 GtCO2 in 2023. While growth in total CO2 emissions has slowed down over the past decade, emissions continue to grow leading to a continued increase in CO2 in the atmosphere and continued global warming.

from GCP

The atmospheric CO2 level is projected to average 419.3 ppm in 2023. This is 51% above pre-industrial levels. If current CO2 emissions levels persist, the remaining carbon budget for a 50% chance to limit warming to 1.5°C could be exceeded in 7 years - essentially eliminating any pathway to holding global temperatures within 1.5°C of preindustrial levels. Though many countries have reduced their fossil CO2 emissions or slowed the growth in emissions, progress is not fast enough and not widespread enough to put global emissions on a downward trajectory towards net zero. 

from GCP

The preliminary data for 2023 show global fossil CO2 emissions are set to reach a record high, with an increase of about  +1.1% (range 0.0% to 2.1%) relative to 2022 level, and expected growth in all fuel types. Projected 2023 emissions decrease in the European Union, USA, and to a lesser extent in the Rest of the World were exceeded by increases in emissions in India and China. Fossil fuel CO2 emissions in India are now above those of the European Union.

from Green Risks

In China (31% of global emissions), emissions in 2023 are projected to increase by 4% (range 1.9% to +6.1%) over 2022. A strong rise is projected for emissions from coal (+3.3%), oil (+9.9%) and natural gas (+6.5%). Growth in 2023 is partly caused by a delayed rebound from significant COVID-19 lockdowns in China in 2022.

In the United States (14% of global emissions), emissions in 2023 are projected to decrease by 3.0% (range -5.0% to -1.0%) over 2022. Decreases are projected for emissions from coal (-18.3%) and oil (-0.3%), while there is a projected rise in emissions from natural gas (+1.4%). The sharp decline in coal emissions is largely driven by a continuation of retirements of coal-fired power stations and cheaper natural gas since 2022. The rise in natural gas consumption in the power sector is largely offset by reduced heating demand resulting from milder winter temperatures in 2023.

In India (8% of global emissions), emissions in 2023 are projected to increase by 8.2% (range 6.7% to 9.7%) over 2022, with projected rises in emissions from coal (+9.5%), oil (+5.3%), natural gas (+5.6%), and cement (+8.8%). Coal growth is largely driven by high growth in demand for power, with new renewables capacity far from sufficient to meet this growth. Emissions in India are now above those of the European Union. India is building coal power generation. Just converting coal generation to natural gas would almost halve emissions. 

In the European Union (EU27, 7% of global emissions), emissions in 2023 are projected to decrease by 7.4% (range -9.9% to -4.9%) over 2022, with projected decreases in emissions from coal (-18.8%), oil (-1.5%), and natural gas (-6.6%). Consumption of both coal and natural gas have been driven down by increased renewables capacity and the continued effects of the energy crisis, with high energy prices and other inflationary factors leading to lower energy demand.

from GCP

International aviation and shipping (2.8% of global emissions) are projected to increase by 11.9% in 2023. It is believed by some that emissions from data centers has already exceeded that level and is growing at a very rapid rate.

Wednesday, December 6, 2023

2023 Dead Zone December Update


At the end of November the Maryland Department of Natural Resources, Old Dominion University, and Virginia Institute of Marine Science announced that the dead zone in the Chesapeake Bay this year was the smallest since monitoring began in 1985. 

The “Dead Zone” of the Chesapeake Bay refers to a volume of hypoxic water that is characterized by dissolved oxygen concentrations less than 2 mg/L, which is too low for aquatic organisms such as fish and blue crabs to thrive. Within the hypoxic area life of the bay dies and a “Dead Zone” forms. The Chesapeake Bay experiences hypoxic conditions every year, with the severity varying from year to year, depending on nutrient and freshwater flows into the bay, wind, and temperature and season. Dead zones form in the warmer months.

The extent of each year’s dead zone is dependent on several factors, including how much nitrogen and phosphorus pollution enters waterways. High precipitation can contribute to the dead zone because it leads to more polluted runoff washing into rivers and streams. Precipitation was below average for most of 2023 delivering less pollution especially during the critical spring season.  

The spring-time nutrient supply to the Bay was relatively low and June was relatively windy, both of which may have contributed to June through August having a low amount of hypoxia. The Dead Zone remained at low to moderate levels throughout June, July, and into August. The Potomac basin has experienced unusual dryness, despite sporadic heavy rains.  Low stream flows carried less nutrients into the rivers. The cumulative deficit over the past 12 water year was around  6 inches in the basin as a whole.

from VIMS

Each year the Maryland Department of Natural Resources measures the actual dissolved oxygen at several points during the summer months in the Maryland portion of the Chesapeake Bay main stem and the size of the Dead Zone. While the Virginia Institute of Marine Science (VIMS), Anchor QEA and collaborators at UMCES, operate a real-time three-dimensional hypoxia forecast model using measured inputs that predicts daily dissolved oxygen concentrations throughout the Bay ( using the National Weather Service wind monitoring data.

Sunday, December 3, 2023

EPA Proposes updated rules for Lead Water Pipes

Last week the U.S. Environmental Protection Agency (EPA) announced a proposal to strengthen its Lead and Copper Rule that would require water systems across the country to replace all lead service lines within 10 years. EPA is also proposing lowering the lead action level down to 10 ppb and improving sampling protocols utilized by water systems. 

EPA estimates that there are 9.2 million lead service lines.  This proposal is expected to cost between $45 billion and $60 billion. There is no funding associated with this proposed change in the Lead and Copper Rule (though the Bi-Partisan Infrastructure bill has $15 billion for lead removal). Water utilities and citizens will have to figure out how to pay for this mandate. Typically, these service lines are owned by both the water utility and the property owner. It is common that utilities only own the portion of the service line until it reaches the property line. However, there are many places like Fairfax where the service line is entirely owned by the property owner it serves. When Washington DC replaced many of their service lines they only replaced the portion that the utility owned leaving the portion of the lead service line owned by the property in place. This often resulted in increased lead exposure from the disturbed line. The proposed rule requires replacement of the entire lead service line.

This is an important regulation because lead can cause damage to the brain and kidneys, and can interfere with the production of red blood cells that carry oxygen to all parts of your body. The greatest risk of lead exposure is to infants, young children, and pregnant women. Scientists have linked the effects of lead on the brain with lowered IQ in children. I am amongst the many scientist who believe there is no safe level of lead exposure. If your home was built before 1990 the only way to know if you have lead in your drinking water is to test.

The U. S. EPA limit for lead in drinking water is currently 15 parts per billion (ppb), but only requires action if limited sample monitoring for lead has exceeded the 15 ppb action level in more than 10% of the homes tested. Cities are only required to test a very small number of homes monthly and the condition and age of the plumbing in the home really determines if lead levels will be elevated.

Lead in drinking water is a national problem mostly associated with older urban areas.  Lead in drinking water predominately coms from the pipes. Lead does not exist in most groundwater, rivers and lakes- the source water for most municipal and private water supplies. Instead, lead in drinking water is picked up from the pipes on its journey into a home.

In the early years of public water supply the water service lines delivering water from the water main in the street into each home were commonly made of lead. This practice began to fade by the 1950’s but was legal until 1988. Lead was also used to solder copper pipes together before 1988 (when the 1986 ban on lead in paint and solder went into effect). Also, until very recently (2011 Reduction of Lead in Drinking Water Act) almost all drinking water fixtures were made from brass containing up to 8% lead, even if they were sold as "lead-free." So even homes built with PVC piping in the 2000’s may have some lead in most of the faucets.

Elevated lead levels can also be a problem for well owners. Lead leaches into the water primarily as a result of corrosion of plumbing and well components. Brass fittings and adaptors usually contains lead levels of 8% or less, but this can still dissolve lead into the water, especially during the first few months of use or in a corrosive water environment. Older submersible pumps had brass components which are a source of lead. Corrosion control techniques such as adjusting pH or alkalinity that are commonly used in public systems are not common in private wells where the decision to install and maintain treatment is solely the prerogative and responsibility of the homeowner. As a result, though 26% of the private wells tested in the  Virginia Rural Household Water Quality program had pH outside the neutral range of 6.5-8.5 , only 5% of private well systems had acid neutralizers installed to control pH and corrosion within the home and 3% had reverse osmosis units that could remove lead among other contaminants. Lead in drinking water is picked up from the pipes and plumbing fixtures on its journey into a home.

The strengthening of the Lead and Copper rule will address many of these risks and  appears to be an improvement that will better protect our inner city communities that are most impacted by lead in drinking water. All lead service lines should be replaced. Those of us on public water need to push to have all lead service lines in our communities replaced. Addressing sources or lead in the home (old copper pipes with lead solder, faucets predating 2014 and the problem of lead in down well equipment will remain the problem of the homeowner.

Wednesday, November 29, 2023

COP 28

The United Nations Climate Change Conference – COP 28 will begin today November 30, 2023 in Expo City, Dubai in the United Arab Emirates (UAE). The conference is scheduled to run until December 12, 2023. Pre meetings have been ongoing since November 24th.  President Biden will not be attending. The United States will be represented by Special Envoy Kerry.

Officials are expecting some 70,000 climate advocates, diplomats and other green groupies will attend the event in Dubai, one of the gleaming modern cities of the middle east built on wealth that fossil fuels have brought to the region. The fact that the world’s most important climate gathering will be hosted by a leading oil producer has sparked outrage among environmentalists and I expect a certain showmanship in the protests. Most people will be restricted to the “green zone” where all the climate theatrics will take place. Access to the blue zone (and true participation in the meeting) is restricted to delegates, admitted observer organizations and accredited members of the press and media. Delegations from all 199 Parties to the UN Framework negotiated in Paris in 2015 are expected to attend.

Under the 2015 Paris Agreement, every country agreed to work together to limit global warming to well below 2 degrees and aim for 1.5 degrees, to adapt to the impacts of a changing climate and to make money available to deliver on these aims to countries not able to afford the costs of adapting to a changing climate. The parties to the agreement committed to create national plans setting out how much they would reduce their emissions called Nationally Determined Contributions (NDC) and agreed that every five years they would update their plans.  

The achievement by a party of its NDC is not a legally binding obligation, nor is a country bound to any particular policies to achieve its target. It can, at any time, revise those targets and policies without legal ramifications. 

from the Global Carbon Project

The problem is that China's CO2 emissions are now more than 230% of the United States and growing rapidly. India's emissions are almost equal to the 27 members of the European Union. Neither nation has any plans to reduce emissions. The United States (by executive order and administrative action) has set a goal to reach 100% carbon-free electricity by 2035 and net zero emissions throughout the economy by 2050. The President by Executive Order also pledged an interim goal of a 50-52% reduction from 2005 levels in economy-wide net greenhouse gas pollution by 2030. 

from the Global Carbon Project

Though China has far surpassed the current CO2 emissions of the United States, our per capita carbon footprint is still one of the highest on earth.

The U.S. carbon emission target is ambitious and would require a carbon-slashing overhaul of the U.S. economy.  The EIA is forecasting that we will not achieve that goal.  Despite the fact that the carbon emissions have been generally trending down since 2005 there is no pathway to reach the 2030 goal. The misleadingly named Inflation Reduction Act (IRA) includes many programs designed to remake the climate impact of the entire U.S. economy. The Congressional Budget Office assigned $391 billion cost to climate programs based on their estimate of the spending from the law's programs related to climate and clean energy. It is a very loose estimate because the law's major environmental tax incentives have no caps. Several investment banks have estimated the true cost of the environmental programs at near or more than a trillion dollars or more. Implementation of the law and its impact will matter. 

Here at home the energy needs of the Commonwealth are changing and growing. Virginia is already the data center capital of the world, and the industry is exploding along with the demand of 24 hours a day 7 days a week power needed to run them. According to Dominion Energy the demand for electricity in Virginia is growing at 7% a year to power the data centers. At the same time under the Virginia Clean Economy Act (VCEA) has the Commonwealth on a short timeline to decarbonize the grid and electrify transportation and heating.

Dominion Energy in its 2023 Integrated Resource Plan (IRP) filed with the SCC this past summer did not have a viable pathway to decarbonize the grid. The picture they paint is that Dominion cannot both meet the power demand of the exploding number of data centers in Virginia and the mandates of the Virginia Clean Economy Act (VCEA). The United States as a whole and Virginia has a mismatch in goals and actions. The time for magical thinking and greenwashing is past.  

Sunday, November 26, 2023

Planting Giant Sequoias Sparks Controversy

Giant Sequoias are conifer trees, which can live for 3,000 years and grow to 300 feet tall and 30 feet wide at their base.  These towering trees grow naturally only on the western slopes of the Sierra Nevada mountains in California. Although they have evolved to be wildfire-resistant, they have suffered greatly in the wildfires of the last 6 years. The giant sequoias are very thick-barked which provides partial immunity to fire and even relies on fire for reproduction; however, scientists say the warming climate has made wildfires worse and deadlier for the trees.

from the USFS

Misguided forestry practices, which sought to suppress beneficial small and moderate fires allowed woodlands to become overly dense and ended up fueling the conflagration. Fire is essential to giant sequoias. Tree-ring records from giant sequoias show that frequent surface fires were the typical pattern of fire occurrence over the past 2,000 years. But this pattern changed after about 1860, when fire frequency declined sharply. During the century from the late 1800s until the late 1900s, fire was rare in many giant sequoia groves due to land use changes and many decades of fire suppression.

Giant sequoias have coexisted with fire for thousands of years. Their thick, spongy bark insulates most trees from heat injury, and the branches of large sequoias grow high enough to avoid the flames of most fires. Also, fire’s heat releases large numbers of seeds from cones, and seedlings take root in the open, sunny patches where fire clears away groundcover and kills smaller trees. But starting in 2015, higher-severity fires have killed large giant sequoias in much greater numbers than has ever been recorded.

Six fires, occurring between 2015 and 2021 killed many large sequoias in numerous groves across the Sierra Nevada. More than 85% of all giant sequoia grove acreage across the Sierra Nevada has burned in wildfires between 2015 and 2021, compared to only one quarter in the preceding century. The Forest Service believes we have reached a tipping point — lack of frequent fire for the past century in most groves, combined with the impacts of a warming climate — have made some wildfires much more deadly for the sequoias.

As part of a multi-year project to improve forest health through reforestation, Sequoia National Forest personnel worked closely with the national nonprofit American Forests to plant over 286,000 trees across 1,380 acres. This included over 14,000 giant sequoia seedlings. While new trees may regenerate on their own after a wildfire,  this cannot happen after high-severity burns when all the overstory trees are dead. In such cases, few, if any, green trees remain. Burned seeds on the forest floor are often unable to develop after experiencing such high temperatures. This is when planting becomes necessary to retain a forest landscape.

Also,  debris and fallen trees need to be cleared from the forest floor to allow seedlings to grow in bare soil, and clumps of burned trees that remain standing need t be removed from some areas. These burnt out trees are structurally weak and may fall soon, endangering the next generation of trees or the forest workers. According to the Forest Service, it is important to not wait too long to plant. If the landscape remains deforested, brush species that thrive in disturbed areas, will quickly carpet the forest, absorbing the moisture and space seedlings need to thrive. Many park land managers worry about vegetation type conversion, which follows high-severity fire and occurs when forested lands transition to shrublands. This can cause an ecosystem shift and is associated with a loss in biodiversity.

Now after two months of planting, a handful of conservation groups filed suit to stop the work last week. The groups contend that the reforestation project, which entails planting tens of thousands of sequoia seedlings on charred hillsides in Sequoia and Kings Canyon national parks, is inappropriate because the burned areas are designated “wilderness,” where human intervention is prohibited. Contrary to what park officials and the Forest Service say, the litigants assert that replanting trees is not needed for the groves to successfully regenerate.

Wednesday, November 22, 2023

Hydrogen Fuel from Waste Plastic

The following is excerpted from a Rice University news release and a MIT news release:

In the early 21st century vehicles using hydrogen-powered fuel cells rivaled electric vehicles with batteries (EVs) as the best way to decarbonize the car industry by replacing gasoline. Today, EVs are way ahead and IRA has clearly chosen their winner- EVs. The big car companies are trying to rapidly electrify their vehicle offerings, but are facing resistance from the consumer. On of the resistant is my husband who really wants a hydrogen car.

Research at MIT found that the lifetime cost of ownership for a fuel cell car has come down in recent years, but remains higher than EVs largely because of the cost of hydrogen fuel. The researchers found the total cost of ownership for hydrogen was around 40% higher than a comparable gasoline vehicle, and about 10% higher than an EV.

EVs have another crucial advantage over hydrogen. There already exists a vast nationwide electrical system. A nationwide transition to electric vehicles creates big challenges, including the need to build a charging network and make plenty of extra electricity to power all these cars and trucks. 

Hydrogen has its own advantages. The fuel can be pumped in less time than it takes to charge an EV battery, and it can deliver longer driving ranges more in line with gasoline cares. Hydrogen more closely resembles the pump-and-go experience everyone knows from using gasoline. However, that experience would require creating an enormous amount of hydrogen and then moving itto refueling stations all over the country. 

Innovations to make hydrogen cleaner and cheaper could help make fuel cell vehicles competitive once again and possibly more desirable. Until now the methods used to make hydrogen it either generate too much carbon dioxide or are too expensive. Green hydrogen, produced using renewable energy sources to split water into its two component elements, costs roughly $5 for just over two pounds.

"The main form of hydrogen used today is 'gray' hydrogen, which is produced through steam-methane reforming, a method that generates a lot of carbon dioxide" said James Tour, a materials scientist. Most of the nearly 100 million tons of hydrogen used globally in 2022 was grey hydrogen derived from fossil fuels, and its production generated roughly 12 tons of carbon dioxide per ton of hydrogen.

Recently researchers from Rice University (James Tour and Kevin Wyss) have found a way to harvest hydrogen from waste plastic using a low-emissions method that could more than pay for itself.

The researchers converted mixed waste plastics into high-yield hydrogen gas and high-value graphene. The researchers exposed plastic waste samples to rapid flash Joule heating for about four seconds, bringing their temperature up to 3,100 degrees Kelvin. The process vaporizes the hydrogen present in plastics, leaving behind graphene — an extremely light, durable material made up of a single layer of carbon atoms.

"When we first discovered flash Joule heating and applied it to upcycle waste plastic into graphene, we observed a lot of volatile gases being produced and shooting out of the reactor," Wyss said. "We wondered what they were, suspecting a mix of small hydrocarbons and hydrogen, but lacked the instrumentation to study their exact composition."

"We know that polyethylene, for example, is made of 86% carbon and 14% hydrogen, and we demonstrated that we are able to recover up to 68% of that atomic hydrogen as gas with a 94% purity," Wyss said. The scientists hope that this work will allow for the production of clean hydrogen from waste plastics, possibly solving both the major environmental challenge of plastic pollution and the greenhouse gas-intensive production of hydrogen by steam-methane reforming.

Sunday, November 19, 2023

Water and Data Centers

We all know that data centers use huge amounts of electricity to power their millions upon millions of chips. However, data centers also use large amounts of water for cooling systems, which ensure that the heat produced by these massive facilities is controlled.

Data center cooling systems use large amounts of water to operate. These systems includes cooling towers, chillers, pumps, piping, heat exchangers / condensers, and air conditioner units in the computer rooms. Additionally, data centers need water for their humidification systems (to avoid static discharges) and facility maintenance. Data centers are either water-cooled or air-cooled, with water-based cooling using evaporative cooling systems more common, particularly for large data centers simply because it is more efficient and effective. Direct contact cooling systems using evaporation can remove and release all of the heat produced inside a data center from the servers and other IT equipment.

In a water-cooled system, water-cooled chillers and cooling towers located on top of the data center roofs produce chilled water, which is delivered to computer room air conditioners for cooling the entire building. In 2021, when Prince William County looked at water consumption for its 25 operational data centers at the time it found that water use varied by season and ranged from about 0.2 to 0.5 gallons per square foot per day. The data centers that Prince William looked at were all relatively small 100,00-250,000 square feet- nothing like the hyper centers being built now. Today, data centers seem to start at a million square feet and move up from there with multiple building campuses.  How water use scales up in multi-story data centers is unknown.

For cooling purposes, data centers typically use potable water, on-site groundwater, or surface water, and rainwater capture systems. Prince William county believes that most data center water comes from potable water supplies. In Loudoun, to some extent, they source non-potable / recycled water, which is treated sewage. In Prince William the treated sewage from UOSA is already used by Fairfax Water to supplement water supply to the Occoquan Reservoir for our drinking water supply.

Water used to cool data centers is either consumed, meaning it evaporates into the atmosphere via the data center’s cooling towers or is discharged, as industrial wastewater, usually to a local wastewater treatment plant. Effective water treatment, either on-site or off-site through a wastewater treatment plant, means that the water can be reused in the cooling system several times, if the water quality (e.g., hardness) is acceptable. Of course, softening the water could help, however, it brings ,pre salt into the waste water.

Data centers reuse water by recirculating the same water through their cooling systems multiple times while replenishing what evaporates. According to Google, this practice saves up to 50% of water when compared with “once-through” cooling systems. However, eventually this reused water needs to be replaced with new water, due to mineral scale formation which will damage the cooling equipment or once the conductivity of the water is too high which could damage the IT equipment. The need for new water results from the build-up of calcium, magnesium, iron and silica, which become concentrated over multiple evaporative cooling cycles.

Amazon Web Services (AWS), Google and others have committed to  being “water positive by 2030,” returning more water to communities and the environment than it uses in its direct operations. This is a very interesting concept. You see, there is no mechanism on Earth for creating or destroying large quantities of water. All the water we have is what's been here, literally, forever- since the planet was formed 4.5 billion years ago. Of all the water on earth only about  3% is fresh: however, only ½% of the water on earth is available for mankind to use. The rest of the fresh water is locked away in ice, super deep groundwater or polluted beyond redemption.

Where exactly are Amazon and Google going to get this excess water they plan to return more of than they use to communities. Obviously, they would have to take it from another watershed or somewhere else. Water is a zero sum game here. No one is making water. The available supply of fresh water is continually renewed by the hydrologic cycle or artificially. Rain drops falls fall to earth and will evaporate, infiltrate into the soil, recharge groundwater or flow along the ground to a stream and ultimately flow into rivers and to the ocean-moving always moving. That is the most basic description.

Building data centers can interfere with the hydrologic cycle.  Covering once open wooded areas with impervious surfaces reduces the recharge of groundwater which impacts stream flow. Changing the use of the land, covering it with buildings, driveways, roads, walkway and other impervious surfaces will change the hydrology of the site reducing groundwater recharge in the surrounding area increasing stormwater runoff velocity and quantity. Once the hydrology is destroyed by development, it cannot be easily restored, if at all.

The Occoquan Reservoir is fed by the Occoquan River which receives up to 40 million gallons a day of the treated discharge of the Upper Occoquan Sewage Authority treatment plant, UOSA.  which  discharges to the river upstream of the Occoquan Reservoir.  A significant portion of the flow (especially during dry periods) into the reservoir is recycled sewage. This treated wastewater is from areas supplied by the Potomac River or lake Manassas so you do not end up with constantly recycling and concentrating the same impurities into the drinking water supply.

In addition, the Occoquan Reservoir receives stormwater runoff, precipitation from the Occoquan Watershed which covers portions of Loudoun, Fairfax, Fauquier, and Prince William counties and feeds the streams and creeks that feed Bull Run and the Occoquan River. Obviously, the Amazon Web Services (AWS) commitment “to be water positive by 2030, returning more water to communities and the environment than it uses in its direct operations” means that either they are incredibly naive about water or plan to take water from another place or disrupt the hydraulic balance to fulfill this pledge.


Wednesday, November 15, 2023

Virginia Needs to Manage the Data Centers

Electricity demand typically inches higher slowly with both economic growth and population growth, less any gains in efficiency. Nationally, electric sales grew just about 5% in the past decade. However, electric growth has been surging in some areas.


from Dominion IRP 2023

Data centers are one of the biggest new electric  power consumers, and demand from them could double by 2030. Some new data centers that have been requesting grid connections from Dominion are as large as 500 megawatts. That is as much as it takes to power hundreds of thousands of homes according to the  Electric Power Research Institute, a nonprofit researcher and advisory. 

In Virginia, Dominion Energy, the state’s largest utility, has connected 75 new data centers since 2019. Statewide electricity sales are up 7% so far this year which is not quite over. According to Dominion’s  IRP, they expect that electric demand to grow by about 85% over the next 15 years. This is unpresented growth in electric demand.


from Dominion IRP 2023

While that is happening, Virginia needs to meet the requirements of the VCEA. In 2020, the General Assembly passed the Virginia Clean Economy Act (VCEA), which mandated a goal of 100% zero-carbon energy generation by 2050 and prescribed increasingly strict Renewable Portfolio Standards (RPS) for Virginia's investor-owned electric utilities.

Under the VCEA is required by law to make the transition from conventional power plants fueled by coal and natural gas to cleaner forms of energy such as wind and solar. Dominion is also required to provide electricity to Grid operators across the U.S. have been warning that power-generating capacity is struggling to keep up with demand for a transition to electric and digital industrialization. The resulting  gaps  in supply could lead to rolling blackouts during hot or cold weather extremes.

While many data centers have made clean energy and sustainability commitments, there is no way to clearly evaluate these claims or ensure they are aligned with the VCEA’s  plans to decarbonize the grid due to non-disclosure agreements and general secrecy around the industry. However, it is clear from Dominion’s 2023 IRP the the power for the data centers is coming from elsewhere- power purchases. As seen in the chart above the states in the PJM with power to sell are West Virginia and Pennsylvania. That power has to be delivered to Virginia and  the public is being asked to subsidize new transmission infrastructure and bear the burden of the compromised viewsheds and land seizures as well as compromise on Virginia’s clean energy and conservation goals in order to meet the massive electricity demand caused by one private industry.

Zoning and land use have always been left up to the counties. It is clear that there is no limit to the desirability of data centers to county supervisors and landowners. The counties of Prince William and Loudoun and increasingly our neighbors have been blinded by the windfall profits to the landowners and the prospect of increased tax revenue, but these windfall profits come at the cost of the data centers’ power demand flat profile, the need for expanding the grid. We have granted data center companies  control over our environment. We are now getting ready to build more gas fired electricity generation facilities to serve them. The data centers will degrade our land and water resources and increase power and water costs for all Virginians.

Sunday, November 12, 2023

Your Water Contains PFAS. Now What?

My younger brother lives in Massachusetts where in 2020, the department of environmental protection (MassDEP) published its PFAS public drinking water standard or Massachusetts Maximum Contaminant Level (MMCL) of 20 nanograms per liter (ng/L), or parts per trillion (ppt) for the sum of the concentrations of six specific PFAS. The six PFAS are: PFOS, PFOA, PFHxS, PFNA, PFHpA, and PFDA. MassDEP abbreviates this set of six PFAS as “PFAS6” and has all public water systems test for them. 

This list of PFAS6 is from the national UCMR 3 (an US EPA  Safe Drinking Water program used to identify emerging contaminants of concern). Roughly 5,000 water systems monitored  for six PFAS back then and according to EPA, 63 water systems serving an estimated 5.5 million individuals detected PFOA and/or PFOS at levels above EPA’s 2016 health advisory level of 70 ppt (separately or combined). Several states took action on their own to protect their citizens. As the US EPA did not take additional action for a decade. Then in March 2023, EPA proposed drinking water standards for PFOA and PFOS at extremely low levels and  higher levels for perfluorobutane sulfonic acid (PFBS), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and hexafluoropropylene oxide dimer acid (HFPO-DA) and its ammonium salt (also known as the GenX chemicals). EPA has not finalized their regulations and the methods of analysis for the regulatory levels has not been yet achieved.

Nonetheless, in Massachusetts my brother received a notice from his water company that they had found a PFAS6 result that exceeded the Massachusetts Maximum Contaminant Level (MCL) for drinking water. He and his partner asked me what they should do. A little background.

There are thousands of PFAS chemicals, and they are found in many different consumer, commercial, and industrial products. This category of chemical has been widely used for over 80 years mainly for their ability to repel oil, grease, water, and heat. PFOS and PFOA found in Scotch Guard and an ingredient in Teflon and traditional Aqueous Film-Forming Foam (AFFF) - the Class B firefighting foam used to fight aviation and other chemical fires -were the first to become widely commercially successful.

PFAS was also used in spray coatings for cans and food packaging. Wash water from light manufacturing or processing. Stain resistant and flame resistant treatments to carpeting, upholstery, clothing. Food with PFAS containing packaging picked up traces of PFAS and it was passed onto people that way, too. Basically, PFAS us ubiquitous. When 3M the former manufacturer of PFOS took blood samples of people exposed to PFAS, they could not find a control group that did not have PFAS in their bloodstream.

MassDEP is working with small public water systems like his to implement treatment for PFAS so that all community drinking water will meet the MCLs. PFAS can effectively be removed by treatment systems at least below the MassDEP MCL, but it is not known how effective they are at achieving the US EPA proposed SDW limit.

Right now the technology out there to remove PFAS is: activated carbon treatment, anion exchange, nanofiltration or reverse osmosis.

Activated carbon treatment is the most studied treatment for PFAS removal. Activated carbon is commonly used to adsorb natural organic compounds, taste and odor compounds, and synthetic organic chemicals in drinking water treatment systems. Adsorption is both the physical and chemical process of accumulating a substance, such as PFAS, at the interface between liquid and solids phases. Activated carbon is an effective adsorbent because it is a highly porous material and provides a large surface area to which contaminants may adsorb. Activated carbon (GAC) is made from organic materials with high carbon contents such as wood, lignite, and coal; and is often used in granular form called granular activated carbon (GAC). At analysis levels available in the past, GAC has been shown to effectively remove PFAS from drinking water when it is used in a flow through filter mode after particulates have already been removed.

Another treatment option is anion exchange treatment, or resins. There are two broad categories of ion exchange resins: cationic and anionic. The positively charged anion exchange resins (AER) are effective for removing negatively charged contaminants, like PFAS. Of the different types of AER resins, perhaps the most promising is an AER in a single use mode followed by incineration of the resin. Once more limitations of analytical method has hindered verification, but like GAC, AER removes 100 percent of the PFAS for a time.

High-pressure membranes, such as nanofiltration or reverse osmosis, have been extremely effective at removing PFAS.  Reverse osmosis membranes are tighter than nanofiltration membranes.  This technology depends on membrane permeability.  A standard difference between the two is that a nanofiltration membrane will reject hardness to a high degree, but pass sodium chloride; whereas reverse osmosis membrane will reject all salts to a high degree exactly how high a degree needs to be confirmed when the test methods are available.  

Though my brother’s water company suggested using bottled water for at risk populations, that may not be a good idea. A study published in August 2021  and led by Johns Hopkins University researchers, found PFAS substances in 39 out of more than 100 different brands of bottled water tested.  Since, I know that his partners is very risk adverse, I advised an interim measure: use a low cost system activated carbon filtration. A couple of years back the Environmental Working Group tested home systems for effectiveness at removing PFAS. Once more they were limited by the then available test methods to know how much PFAS was removed. The systems EWG recommends were inexpensive and 100% effective to the limit of analysis of removing PFAS.

So, you can just go the EWG website and click through one of the less expensive water filters and give it a try.  After a reliable test method and verification of removal takes place you can reevaluate this decision.

Wednesday, November 8, 2023

Groundwater an Essential Part of our Water Supply

Groundwater is the moisture and water that exists in the spaces between rocks, the pores in the soil and fractures in the geology-the invisible portion of the water cycle. Groundwater is renewed through precipitation, which is often seasonal, but can be extracted year-round. Provided that there is adequate replenishment, and that the source is protected from pollution, groundwater can be extracted indefinitely and can be robust in the face of drought.

However, mankind is rarely prudent. Increase the amount of groundwater extracted, then slowly over time the aquifer is used up. Development adds people and industry increasing the demand for water while adding roads and buildings that prevent the infiltration of precipitation into the ground.  Essentially, reducing the recharge of the aquifer while increasing the demand for water a potentially unsustainable combination. Increase water use or reduce recharge by eliminating forested areas and replacing with compacted soils (lawns that need to be watered), pavement, buildings and over time the aquifer will become exhausted.

Groundwater is both used for water supply and serves to support steam flow between rain storms. Groundwater comes from rainwater and snow melt percolating into the ground. Typically, the deeper the well the further away is the water origination and the older the water. The groundwater age is a function of local geology, the amount of precipitation and the rate that water is pumped out of the aquifer. Geology also determines the ease with which water and contaminants can travel through an aquifer and the amount of water the land can hold. The land surface through which groundwater is recharged must remain open and uncontaminated to maintain the quality and quantity of groundwater.

The groundwater cycle in humid and arid regions differ fundamentally from each other. In humid climates, with high rainfall, large volumes of water seep into the groundwater, which contributes actively to the water cycle feeding streams, springs and wetlands during periods when the rainfall is lower. In semi-arid and arid climates, there is by contrast practically no exchange between the surface water and groundwater because the small volume of seepage from the occasional rainfall only rarely penetrates the thick and dry (unsaturated) soils. That groundwater tends to be much deeper and isolated from surface contact. In currently arid areas groundwater resources are only minimally recharged. Our understanding of the complete water cycle is still only rudimentary.

We do know that groundwater availability varies by location. Precipitation and soil type determines how much the shallower groundwater is recharged annually. However the volume of water that can be stored is controlled by the reservoir characteristics of the subsurface rocks. Water resources can be used sustainably only if their volume and variation through time are understood. However such information is often lacking. Hydrology as a science is very young and so little is known. Any attempt to accurately model the groundwater component of the water cycle requires adequate measurements and observations over decades. The computer models in common use in the United States only address the shallower groundwater and surface water interactions and tend to assume linear relationship which scientists are finding is not accurate.

Groundwater is usually cleaner than surface water. Groundwater is typically protected against contamination from the surface by the soils and rock layers covering the aquifer. This is the only available clean drinking water in many parts of the world. However, rising world population, changes in land use and rapid industrialization are increasingly place groundwater in jeopardy. Once contaminated, groundwater is very difficult to clean and often after removal of contaminated plumes only long term abandonment of use to allow for natural attenuation is the only possible course of action. As droughts and water shortages appear the value of groundwater has begun to be more fully appreciated. Precious groundwater resources increasingly need to be protected and well managed to allow for sustainable long-term use.

Water-table aquifers are usually shallower than confined aquifers and because they are shallow, they are impacted by drought conditions and surface contaminants more easily than confined aquifers. Thus, most public supply water wells draw from the deeper confined aquifers. The water is drawn from the fine-grained confining layers called aquitards. Water enters these aquitards very, very slowly and the danger in utilizing them for supply is that they become overdrawn.  When that happens an irreversible compaction of the fined-grained confining layer occurs and there is permanent subsidence. The land surface falls, permanently reducing the storage capacity of underground aquifers, threatening future water supplies.

The demand for water is rising as population, economic activity and agricultural irrigation grow. We need to manage our water resources in a sustainable way if we are to have a future. To survive over time, a population must live within its available resources. Water is essential for life. We need water for drinking, bathing, irrigated agriculture and industry. A large portion of the fresh water on earth is groundwater. It moves and changes over time and there limits to the amount of groundwater available for extraction from an aquifer. To be sustainable, the amount of groundwater removed from an aquifer needs to match the recharge rate.