Record for Days without Rain

Northern Virginia is usually a fairly wet location. It rains about 44 inches a year on average. However, that is on average. The DC metro region has not had rain in 32 days. According to the ICPRB the region’s longest dry streak was in 2007 and ran 34 days.  At this time, no appreciable rainfall is expected in the next week so it looks like we’re going to break the record.

“A wide range of evidence indicates that the earth has been warming over the past century, causing glaciers and sea ice to melt in many parts of the world, sea levels to rise, and patterns of precipitation to change. Most scientists agree that these trends are likely to continue and to accelerate due to increasing levels of carbon dioxide and other “greenhouse” gases in the atmosphere. Likely changes in temperatures and precipitation will affect the availability, use, and management of water resources.”

“According to projections from climate models, temperatures in the Potomac basin will rise whereas precipitation could rise or fall. Both temperature and precipitation have an impact on stream flows, and the range of available climate projections lead to a wide range of potential changes in water availability in the basin.”

"The primary climate models have predicted it is likely that storms will be more intense and droughts will be longer and more severe going forward. “Results project changes in long-term average summer basin-wide stream flows ranging from -35 percent to +42 percent, with a median of +2 percent, over the period between 1995 and 2040.” The region has been preparing for this variability by building billions of gallons of water storage still years away from being completed.   COOPClimateChangeFactsheet_Apr22-2013.pdf

On a positive note, the upstream drinking water reservoirs that we have in service are nearly full. These reservoirs would be used to supplement downstream flow in the case of a severe drought. The region has been planning for water supply shortages for years. The extended dry conditions have increased the area of Moderate Drought Conditions (D1) in the Potomac River watershed by almost 30% since last week alone. ICPRB staff is monitoring the river’s flow and keeping in contact with the region’s stakeholders. Due to low flow conditions and no rain in the forecast in the next 10 days it is expected that ICPRB will begin Drought Monitoring any day now. 

 The impacts from Tropical Storm Helene at the end of September hit the region with a excess precipitation a month ago. Since then, above-average temperatures and little precipitation have led to decreases in soil moisture for much of the Commonwealth as well as slight decreases in streamflow. Gages throughout much of Virginia monitoring network (which excludes the Potomac Watershed) indicate normal levels. Groundwater levels in most of the Commonwealth remain low and continue to exhibit seasonal and drought related declines, with Northern Virginia and Shenandoah regions reading less than the 5th percentile in groundwater. The 8-14 day weather forecast predicts normal to above normal temperatures and chances of slightly below average precipitation.

The most recent weekly U.S. Drought Monitor (USDM) web page map for Virginia (released October 31, 2024) showed abnormally dry (D0) conditions mapped across approximately 90.00 % of the Commonwealth and moderate drought (D1) conditions mapped across approximately 13.45 % of the Commonwealth. This is a significant increase from the previous week as the effects of the Tropical storms of September fade.

Farming Fish Not Environmentally Sound

 

Spencer Roberts, Jennifer Jacquet, Patricia Majluf, Matthew N. Hayek; Feeding Global Aquaculture; 2024/10/18; DOI: 10.1126/sciadv.adn9698; Journal: Science Advances Volume: 10; Issue: 42; Feeding global aquaculture

The below article is excerpted from the article cited above and the Press Release from the University of Miami and some thoughts from "Salmon Wars" by Douglas Frantz and Catherine Collins.

 

A study published this month in the journal Science Advances suggests that fish farming, or aquaculture, relies on much larger quantities of wild-caught ocean fish than previously calculated. These miscalculations have helped to portray fish farming as uniquely efficient or sustainable. Instead, the above cited study portrays fish farming like other forms of animal farming, albeit with a uniquely high reliance on wild fish extraction.

This wild fish extraction to feed the farmed fish also diverts millions of tons of food-grade fish (e.g., anchovies and sardines) and nutrients from countries with high rates of hunger to farmed aquatic animals (e.g., salmon and shrimp) intended for luxury markets of the world. Millions of people in Africa rely on fish for protein.

For too long, the fish-farming industry has wrapped itself in a cloak of virtue, asserting that it is feeding the world and putting healthy food on the table. The use of fish trimmings (heads, tails and guts) in feed is seen by many as a sustainable option and evidence of a circular economy in fish farming.  That is an illusion. The use of by-products and trimmings has not phased out the capture and use of whole wild fish in feeds for aquaculture. The offshore aquaculture industry is growing so rapidly that the wild-caught fish is not being replaced in their feed. Instead, other feed sources are just supplementing wild fish use.

Small fish such as anchovies and sardines are among the main species targeted for aquaculture fishmeal. The issue is that wild animals depend on these fish for food as well as the local communities. The 3,400-mile-long Atlantic coast of West Africa and the Pacific coast of Peru have been overfished to the point of threatening the viability of the native communities who depended on fishing and fish for survival. Penguins in Cape Town are declining largely due to the intense fishing pressure on sardines and anchovies and other species are also under stress.

The research cited above provides a reassessment of the "fish-in:fish-out" (FI:FO) ratio for global fed aquaculture to evaluate the efficiency and sustainability of aquaculture. By analyzing multiple industry-reported datasets, the researchers provided a range of estimates and highlighted uncertainties in current reporting practices. They found that the aquaculture industry relies more heavily on wild fish extraction than previous research had suggested.

The findings indicate that the ratio of wild fish inputs to farmed fish outputs is 27% to 307% higher than previous estimates, ranging from 0.36 to 1.15 compared to an earlier estimate of only 0.28. When accounting for wild fish mortality during capture and excluding unfed aquaculture systems, the ratio rises even further to 0.57 to 1.78. (The lower number reflects the use of terrestrial crops in some aquaculture species.) For carnivorous farmed species like salmon, trout, and eel, wild fish inputs likely exceeded twice the farmed fish biomass produced.

"Our study reveals that the aquaculture industry relies more heavily on wild fish extraction than previous research has suggested,” said Spencer Roberts, a doctoral student at the Rosenstiel School in the Department of Environmental Science and Policy, and lead author of the study. “This demonstrates the scale at which aquaculture could be impacting marine ecosystems."

The research team's approach included accounting for previously overlooked sources of wild fish in aquaculture feed, such as trimmings and byproducts from wild-caught fish. They also incorporated collateral fishing mortality, including "slipping"—a practice where unwanted catch is released but a large portion of the animals often do not survive. By analyzing multiple industry-reported datasets, the team provided a range of estimates and highlighted uncertainties in current reporting practices.

The researchers stress that while their study provides a more comprehensive view of aquaculture's environmental impacts, further research is needed to fully understand the sector's effects on issues such as nutrient pollution, habitat destruction, and the spread of diseases to wild fish populations.

Matthew Hayek, an assistant professor in the Department of Environmental Studies at New York University and the  corresponding author of the study, stated "It's crucial that we have a more complete understanding of the industry's impact on both marine and terrestrial ecosystems and reduce these uncertainties.” He emphasizes that even with the wide uncertainty ranges reported, the impacts are still larger than previously reported, and “most offshore finfish aquaculture facilities produce carnivorous fish, and therefore are responsible for depleting far more fish from the ocean than what they can produce.”

COP 29

The 29th Conference of the Parties (COP29) will take place in Azerbaijan next month, November 11th and 22nd 2024. For 2 weeks, delegates from nations across the globe will convene to discuss the next steps in the ongoing fight against  climate change and pretend that it is still possible to keep global warming under 1.5 degrees Celsius. It’s not. We are sitting on a melting ice cube.

Once more the climate three aims have officially been outlined as COP29’s ‘Framework for Action. These are:

• Reduce emissions to keep global warming under 1.5 degrees, while leaving no one behind.
• Inclusive process for inclusive outcomes.
• Enhance ambition and enable action.

Nice words, but in truth since the signing of the Paris Climate Accord, global greenhouse gas emissions have continued to rise. We are further from net zero emissions than we were in 2015.  ‘While leaving no one behind’ is a nice thought and signals an interest in ensuring that developing nations and vulnerable communities are included in the discussions and subsequent actions. This is the second aim, to ensure an inclusive process. Enhancing ambition and enabling action. Increasing the ambition is about increasing the pledges that the nations have made.

Under the Paris Agreement China has only agreed to stop growing their CO2 emissions by 2030, and India made no pledged reductions. At COP 26 in 2021 India signed an agreement to reduce coal and increase its renewable energy generating capacity to 500 gigawatts by 2030 with the goal of reaching net-zero CO2 equivalent emissions by 2070. However, In November 2023 India approved a plan that roughly doubled coal production, reaching 1.5 billion tons by 2030 and included more than quadrupling its underground coal production by 2030.  

Meanwhile the news from China is no better. In fall 2023 China announced that coal-fired power capacity would rise by more than 200 Gigawatts by 2030. That increase is equivalent to the entire energy production of Canada. Let’s be honest here despite promises made year after year the CO2 emissions of the planet have grown at a compounded annual rate of 1.8% per year since 1990. Our situation is worse not better, yet, the growth in fossil fuel emissions may be slowing.

Ahead of the meeting Azerbaijan announced the Climate Finance Action Fund (CFAF) to invest in climate action in the developing world. I believe that is what enabling action is about providing money.  CFAF will be capitalized with contributions from fossil fuel producing countries and companies across oil, gas and coal, and Azerbaijan will be a founding contributor. Members will commit to transfer annual contributions as a fixed-sum or based on volume of production.

The United States is an oil and gas producing country. However, we may also be moving towards financial disaster. This month it was reported that the federal budget deficit for fiscal 2024 came in at $1.83 trillion that will have to be funded by selling treasury bonds. That’s 13% larger than the year before adjusting for timing shifts in outlays. It also comes despite an 11%, or $479 billion, increase in receipts for the fiscal year that ended September 30, 2024. Total government revenue was $4.92 trillion, individual income taxes rose 11% or $249 billion. Corporate income taxes rose 26% or $109 billion.

The deficit ought to decline when revenues rise significantly, but the problem is that spending also rose 11% by $699 billion to $6.75 trillion. Social Security rose 8% and Medicare rose 9%. Interest payments on the national debt are now larger at $950 billion than the entire defense budget of $826 billion or Medicare $869 billion. Interest payments accounted for 14% of the budget. The total national debt is 97% of GDP. 

The fiscal path of the Unite States is unsustainable and limits our nation’s ability to maintain a world leadership position (which ensures our ability to sell bonds). Worse than that, it limits our ability to finance climate adaptation in our own country, continue paying full social security benefits and providing health benefits through Medicare without rationing care and contribute to CFAF funding. In August, Fitch downgraded the U.S. government debt, citing "steady deterioration in standards of governance" on "fiscal and debt matters." 

The COP29 leadership states that they are working with a ‘broad range of international stakeholders’ to ensure that all perspectives are considered and that the outcomes of the conference are based on ‘shared solutions.’  I have no idea if this means that there will be renewed effort to move the needle or that world events and the forming of global axis will overshadow these urgent goals. We are sitting on a melting ice cube and we just keep talking..

Climate Overshoot is a Fantasy

Schleussner, CF., Ganti, G., Lejeune, Q. et al. Overconfidence in climate overshoot. Nature 634, 366–373 (2024).  https://doi.org/10.1038/s41586-024-08020-9

According to the data from the Global Carbon Project and the Rhodium Group, CO₂  emissions from mankind’s activities continue to grow . This brings CO₂  emissions to a record high above the pre -COVID-19 levels.

While emissions are declining in 26 countries, these efforts remain insufficient to reverse the growth in global  emissions in China and India. Growth in total CO₂  emissions for our planet – the sum of fossil and land-use change 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.

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. CO₂  emissions in India are now above those of the European Union.

As the  Intergovernmental Panel on Climate Change, IPCC sixth report showed that:

• Climate Change is already affecting ecosystems globally
• The planet is being impacted unevenly
• Despite pledges made the world is still on track for a 2-2.9 degree Celsius warming
• China and India are not our friends and their emissions will continue to grow significantly.

Last year the Washington Post analyzed 1,200 pathways to 1.5 degrees C. The Washington Post could not find a single pathways with  assumptions that did not involve magical technological development that didn’t include temperature overshoot. A recent article in New Scientist Magazine summed up the situation perfectly.

“It is clear that the world is going to exceed the 1.5°C target for global warming, leading to an increasing focus on plans to cool it down again by removing carbon dioxide from the atmosphere..”

Now the article cited above and published this month in Nature magazine brings into question whether we will even be able to bring the temperature back down after an overshoot; and even if we can bring the planetary temperature back down, some changes in the plant can’t be reversed.  In the analysis cited above the authors adapted existing suites of climate models to capture different elements of the climate response during the warming phase and the long-term phase after net zero emissions is achieved and carbon is removed from the environment. They modeled:

• The expected warming for a given quantity of cumulative emissions until net-zero CO₂.
• The expected warming or cooling for a given quantity of cumulative net-negative emissions after net-zero CO₂.
• The continued temperature response after net-zero CO₂ emissions are achieved and sustained
• What they found was For a range of climate impacts, there is no expectation of immediate reversibility after an overshoot. 

What they found was For a range of climate impacts, there is no expectation of immediate reversibility after an overshoot. This includes changes in the deep ocean, marine biogeochemistry and species abundance, land-based biomes, carbon stocks and crop yields, but also biodiversity on land. An overshoot will also increase the probability of triggering potential Earth system past tipping points that cannot be restored. Sea levels will continue to rise for centuries to millennia even if long-term temperatures decline.

The analysis also showed there is no guarantee that we will be able to bring the temperature back down. The sad truth appears to be that the climate change will impact life on earth. Species that go extinct due to loss of habitat cannot be brought back to life. If the ice sheet collapses, even if temperatures are restored it will take millennia to restore them and the list goes on. Restoring the temperature will not restore the lives that are lost. It is hoped that with adaptation to the changing climate some of mankind will survive this century. 

We have just passed the Jewish Days of Awe. On Yom Kippur, the Day of Atonement, Jews recite (more than once) the prayer Unetanneh Tokef, Jews believe God reviews our fates and decides who will live and who will die in the coming year. The older I get, the more appropriate the prayer feels for all of mankind. Below is a portion of the English translation. 

On Rosh Hashanah it is inscribed,
And on Yom Kippur it is sealed.
How many shall pass away and how many shall be born,
Who shall live and who shall die,
Who shall reach the end of his days and who shall not,
Who shall perish by water and who by fire,
Who by sword and who by wild beast,
Who by famine and who by thirst,
Who by earthquake and who by plague,
Who by strangulation and who by stoning,
Who shall have rest and who shall wander,
Who shall be at peace and who shall be pursued,

Dominion 2024 IRP

Last week Dominion Energy released its 2024 Integrated Resource Plan (IRP)and filed it with the State Corporation Commission(SCC).  In the submission, Dominion details how it plans to meet electricity needs and demands over the next 15 years. 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). There is simply too much growth in demand for electricity. Dominion estimates that the cost for all plans is a net present value of $94 billion-$103 billion. In all scenarios generating capacity will only be added, there are no retirements.  There were fewer differences than the portfolio in the past because of the need under all scenarios for more capacity to generate electricity. 

The 2020 VCEA is the state’s law outlining a path to decarbonize the electric grid by 2050. VCEA requires the Commonwealth to retire its natural gas power plants by 2045 (Dominion) and 2050 (Appalachian Power). These facilities currently comprise 67% of the current baseload in-state generation as well as 100% of the power plants that meet peak demand. About 30% of Virginia’s generation is from nuclear. Under the VCEA Dominion can run carbon-emitting facilities until 2040 and must build a stated amount of solar and wind generation.  Only by petitioning the SCC and demonstrating a need to maintain grid reliability can they continue running their fossil fuel plants. When the VCEA was crafted, they did not foresee the explosive demand for electricity that unconstrained data center development would drive. I assume that Dominion will comply with the new EPA rules for power plants. In their IRP that cost is given as $6-$6.5 billion.

In the discussion below I have taken excerpts from the IRP. To read the full report, click on this link. 2024 VA IRP (cdn-dominionenergy-prd-001.azureedge.net)

Dominion Energy Virginia does not produce all the electricity it delivers and sells. Dominion Energy is a member of PJM Interconnection, LLC (PJM), the regional transmission organization coordinating the wholesale electric grid in the Mid-Atlantic region of the United States. PJM other members supply a significant amount of the energy used in Virginia. Over the last decade, Virginia has depended on power purchases for an increasing share of total energy served. In 2021, the Dominion purchased 14% of its total energy served from the PJM market, in 2022 that number increased to 21%, and in 2023 that number increased again to 22%.

However, in February 2023, PJM found that the current pace of bringing new power generation to market would be insufficient to keep up with expected retirements and demand growth in the foreseeable future. For the first time in recent history, PJM could face the projected total capacity from generating resources would not meet projected peak loads by the 2028/2029 Delivery Year and beyond.

The auctions for the PJM  base power residuals published for the 2025/2026 Delivery Year resulted in significantly higher prices for the Dominion service area.  The market clearing price for the Dominion service area was $444.26/MW-Day which is over 60% higher than the Regional Transmission Organization (“RTO”) clearing price of $269.92 and 15 times higher than the previous 2024/2025 RTO clearing price of $28.92/MW-Day. Constrained supply has pushed the price higher.

Dominion states that the 2024 IRP focuses heavily on reliance on utility resources, recognizing the limits on the ability to import power from elsewhere in PJM. An over-reliance on imported power creates reliability and price risks for Dominion customers, particularly as conventional generation resources have retired and will continue to retire across PJM for economic and environmental compliance reasons.

The need for additional in-state generation, transmission, and distribution resources to reliably supply power is acute.  Demand for power is forecasted to increase 5.5% annually over the next decade and double by 2039 in Dominion's delivery zone within PJM. In this year’s IRP Dominion states that this time they are confident in its Data Center Load Forecast and detail the factors that give them that confidence. Under the VCEA Dominion is supposed to replace all carbon-emitting facilities by 2040, but  the growth they are forecasting make that impossible. All the new generation built will go to supply the increased demand from data centers. The big drivers of current and future growth include migration to the cloud as businesses outsource information technology functions, smartphone technology and apps, 5G technology, digitization of data, and artificial intelligence (“AI”). From storing videos to hosting AI systems that allow consumers to create documents, web pages, music, and more, data centers serve the needs of the public every day.

Dominion Energy’s Data Center Load Forecast is based on existing contracts with customers. As projects progress, customers enter into a series of contracts with binding financial commitments. Dominion Energy regularly reviews this contractual approach to ensure that its Data Center Load Forecast reflects projects that will come to fruition.. Dominion provides a 15-year data center load forecast to PJM, who independently reviews and verifies before incorporating it into PJM’s own forecast.

While market purchases have been, and will continue to be, part of meeting customers’ needs, overdependence on market purchases could be cause for concern. Power may not be available for purchase when it is needed during extreme weather events or other demand spikes. This risk is expected to be exacerbated in the future by the new environmental regulations, the PJM capacity market reform, and other states’ energy policies.

Dominion’s  generation and transmission adequacy is a vital issue that must be addressed at the state level because of the VCEA. There are challenges to the siting and development of new power generation resources across all technologies. Dominion Energy supplements its generation fleet with third-party PPAs. The Company has existing contracts with renewable energy and fossil based PPAs, for approximately 1,277 MW (nameplate capacity not functional capacity) as of the end of 2023.

Over the past two decades, Dominion has migrated away from coal use towards natural gas and increased renewables. This has resulted in significant reductions in carbon dioxide (“CO2”) emission intensity. CO2 intensity is the quantity of emissions per megawatt hour (“MWh”) delivered to customers. This calculation includes emissions from any source used to deliver power to customers, including Company-owned generation, PPAs, and net purchased power. As shown below  CO2 intensity has decreased by 57% since 2000.

For over half a century, nuclear energy has provided reliable, affordable, and zero carbon electricity to meet customer load demands and remains a fundamental component of the transition to net zero emissions. Dominion Energy is extending the life of its nuclear units and considering additional nuclear energy resources in the form of small modular reactors (“SMRs”). SMRs are a classification of nuclear reactors with an output of approximately 300 MW of electricity per reactor. This output is about one-third of the generating capacity of traditional nuclear power reactors. The modular nature allows for portions of the plant to be factory-fabricated and delivered to the site.

Given the small size and modular construction process, Dominion states it is possible to locate SMRs on a wide variety of sites, including retired fossil-fuel generation sites (hello Possum Point), existing nuclear power generation sites (Lake Anna), other industrial areas, and areas closer to the electric demand. In this IRP Dominion has assumed that SMRs will be developed and available to meet the generation shortfall. Based on updated capital, operating and maintenance costs, continued progress of licensing timelines, it is conceivable that the deployment of SMRs could be further accelerated by Dominion.

Nonetheless, natural gas will remain essential to continue providing electricity to the customers. Natural gas power generators are dispatchable resources that play a vital role in supporting increased reliance on intermittent renewable resources. With flexible operating characteristics, giving them the ability to follow load, natural gas units support the grid to generate energy when it is needed, thus allowing the units to turn on, run during the times of peak energy usage, and/or when intermittent resources are not available and then turn off. This mitigates the risk of insufficient generation to meet large swings in energy output of intermittent generation. (No wind. Night time. Overcast days.), 

In the 2024 IRP, Dominion presents four generation mixes that will meet customers’ needs in the future under different planning assumptions. These Portfolios are designed using constraint-based least-cost planning techniques and proven energy generation technologies. The chart below shows the capacity by generation type, but the full breakout can be found in  Appendix 5C of the IRP.

Dominion made the following key observations on the energy mix:

• Due to changes in the PJM Market and increasing load forecast, generation capacity was the controlling factor.
• Nuclear units are essential for ensuring reliability.
• VCEA resources (i.e., solar, wind, battery storage) will make 3% of energy supplied  in 2025, and grow to approximately 30% in 2039.
• Natural gas-fired generators will increase in total generating capacity with the addition of almost 6 GW of new natural gas-fired generation. However, due to growth in demand natural gas will decrease from just below 50% of generation in 2025, to below 30% by 2039.
• There were fewer differences than the portfolio in the past because of the need under all scenarios for more capacity to generate electricity. All Portfolios built the maximum amount of new offshore wind, SMRs, and natural gas that they were allowed to build.
• The NPVs for the Portfolios that include the new suite of EPA regulations is $6 to $6.5 billion more costly than those that do not.
• By 2030, all Portfolios show the proportion of energy purchases from the market approaching their upper limit set in the model of 20%, and stays near this limit through 2039. Dominion can only meet long-term demand if it relies on the PJM market to satisfy up to 20% of its customers’ energy needs. 

Figure 4.2.1.1 below shows a comparison of a typical bill for a residential customer using 1,000 kWh, projected utilizing the Company Methodology (Dominion's) and the Directed Methodology (SCC's  approach).

Africa Water and Food Problems exacerbated by Drought

“Hunger and food insecurity can lead to instability. There is a vicious feedback loop between conflict and hunger currently at play in dozens of countries around the world. War drives hunger and hunger drives war.” - Chase Sova and Eilish Zembilci

Drought can  cause hunger and food insecurity especially in areas of subsistence farming. According to the United Nations, “more than half of global population growth between now and 2050 is expected to occur in Africa. Africa has the highest rate of population growth among major areas. The population of sub-Saharan Africa is projected to double by 2050. …that region will play a central role in shaping the size and distribution of the world’s population over the coming decades.” Unfortunately, they are a very poor  and scientists tell us that sub-Saharan Africa is one of the most vulnerable parts of the world to climate change because of a high dependency on subsistence, rain-fed agriculture and natural resources.

This week, the United Nations’ food agency has declared a food crisis (famine)  in five countries — Lesotho, Malawi, Namibia, Zambia, and Zimbabwe. The individual countries have all declared national disasters over the drought and hunger. These countries are all part of sub Saharan Africa and  the U.N.’s World Food Program estimates that about 21 million children in sub Saharan Africa are now malnourished as crops have failed.

In a press conference in Palais des Nations in Geneva, Switzerland the World Food Program Spokesperson for Southern Africa, Tomson Phiri appealed to Western Nations for relief funds. “At the request of governments, WFP has started to provide food assistance and critical support in transport, logistics and food procurement. Against soaring global needs, we have only received one fifth of the US$369 million needed to provide assistance to millions in Southern Africa. 

While the funding received so far has allowed WFP to begin relief food distributions, a significant funding gap remains, which threatens to jeopardize plans for a full-scale response through to the end of the lean season in March next year.” 

Meanwhile, the drought has impacted water availability in South Africa reducing water availability in the Vaal River system. Rand Water, the company that supplies the cities of Johannesburg, Pretoria and Ekurhuleni is in danger of cutting off water supply. This past week they announced that if municipalities do not act on its recommendations to fix leaks and conserve water, the water storage for the cities will soon be depleted. Rand Water can’t pump more water from the Vaal River system and reservoir because of the limits of its extraction license with the Department of Water and Sanitation.

The country’s water-supply systems have deteriorated because of inadequate maintenance, sabotage, a lack of planning for population growth, mismanagement, corruption and political infighting. The South African government that pushed out the completion of a $2 billion project to expand reservoirs to increase supplies from Lesotho, a mountainous enclave in South Africa, by a decade until 2029.

Now with the drought, Rand Water is withdrawing more water than it is authorized 1 680Mm³/Ann vs authorized 1 347Mm³/Annum. When there wasn’t a drought they were able to do this, but not now. Will the conflicts in the area grow as water and food become less available. 

Pesticide Contamination in the Potomac Watershed

Samuel A. Miller, Kaycee E. Faunce, Larry B. Barber, Jacob A. Fleck, Daniel W. Burns, Jeramy R. Jasmann, Michelle L. Hladik, Factors contributing to pesticide contamination in riverine systems: The role of wastewater and landscape sources, Science of The Total Environment, Volume 954,2024, 174939, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2024.174939.

The article below is excerpted from the research article cited above.

The Potomac River Watershed is the second largest watershed (36,750 km²) within the Chesapeake Bay watershed and contributes about 15 % of the total streamflow to the Bay. The mainstem of the Potomac River has minimal flow regulation and is freshwater and the major source of drinking water for the  Washington, D.C. metropolitan area- Loudoun Water, Fairfax Water, Leesburg Water, WSSC and the Washington Aqueduct.

 Population in the Potomac River Watershed more than doubled from 1970 (3.2 million) to 2020 (6.9 million). The majority of development during this period occurred in the Washington, D.C. metropolitan area, where about 84 % of the watershed’s population resided as of 2020. To accommodate population growth, forest and agricultural lands have been reduced and public water supply and wastewater treatment systems have been expanded drawing on the Potomac River itself. A majority of public-supply withdrawals (80 %) in the Potomac River Watershed are from surface water.

The Potomac River Watershed contains a varied landscape consisting of steep mountains, rolling hills, broad valleys, and plains. The majority (53 %) of the basin is forested, 23 % is agricultural, and 13 % is developed whereas smaller remaining portions contain water, wetlands, and barren land cover. 

According to Miller et al wastewater discharges, although treated and in compliance with existing regulations, can be a continuous source of organic contaminants, including pesticides, to the Potomac River and  rivers worldwide. Pesticides can be introduced to wastewater treatment plants by what goes down-the-drain or flushed down the toilet at homes and businesses. Urban and suburban stormwater enter the watershed and may include sources of pesticides from residential lawns and gardens, leaky septic systems, or outdoor pest control, including applications to impervious surfaces. Separate sanitary sewer systems can also contain water sourced from groundwater via infiltration through cracked or broken sewerage pipes.

Frequently, pesticides are transformed or not completely removed during conventional wastewater treatment which are not designed to address these contaminants and are discharged in the wastewater treatment plant effluent to receiving waterbodies. In addition, some wastewater treatment plants receive industrial discharges. Although pesticides are frequently introduced to aquatic environments from agricultural and developed land-use nonpoint sources, wastewater treatment plant-derived pesticides are of particular concern because they are continuously discharged to receiving waters that often serve as source water for drinking water plants. Discharge from the largest wastewater treatment plant in the study area, UOSA,  is one of the largest indirect potable water reuse sources in the world (Jeffrey et al., 2022).

An integrated model was developed for the Potomac River watershed to determine the amount of accumulated wastewater percentage of streamflow and calculate predicted environmental concentrations (PECs) for 14 pesticides in non-tidal National Hydrography Dataset Plus Version 2.1 stream segments. Model predicted environmental concentrations were compared to measured environmental concentrations from 32 stream sites that represented a range of land use to evaluate model performance and to assess possible non-WWTP loading sources. Statistical agreement between PECs and MECs was moderate- it was strongest for insecticides, followed by fungicides and herbicides.

Among the target pesticides, PECs generally had the best agreement with MECs (Fig. 6) for insecticides (ρ = 0.52, p < 0.01), followed by fungicides (ρ = 0.36, p < 0.01) and herbicides (ρ = 0.20, p = 0.14). Individual pesticides with significant correlations between PECs and MECs included dinotefuran (ρ = 0.87, p < 0.01), thiabendazole (ρ = 0.82, p < 0.01), fipronil (ρ = 0.61, p < 0.01), and tebuconazole (ρ = 0.53, p = 0.02). Significant correlations were found between these individual pesticide concentrations and water quality indicators of wastewater presence including the optical brightener-to-fluorescein ratio, and boron concentrations, confirming that wastewater treatment plants effluent likely is a source for these pesticides.

Target pesticide corrected-MECs that had the most significant correlation with estimated agricultural use included atrazine (ρ = 0.54, p < 0.01), clothianidin (ρ = 0.35, p = 0.05), metolachlor (ρ = 0.62, p < 0.01), and simazine (ρ = 0.70, p < 0.01). The lack of agreement between corrected-MECs and estimated pesticide use on agricultural land for the remaining target pesticides indicates there may be sources beyond wastewater treatment plant effluent and agriculture during stream base flow conditions.

Pesticides are commonly used within the Potomac River Watershed for non-agricultural purposes, such as: (1) maintenance of lawns, gardens, and golf courses, (2) defoliation of rights-of-way, and (3) structural pest control (Ator et al., 1998). Pesticide usage rates are not well documented for these categories, which makes source identification difficult.

The U.S. Environmental Protection Agency estimated in 2012 that more money was spent on insecticides used in home and gardens ($2,650,000,000) than in agriculture ($1,499,000,000) and industry ($700,000,000) combined, and overall, 27 million kilograms of pesticides were applied to home and garden areas (Atwood and Paisley-Jones, 2017). Homeowners frequently apply high rates of pesticides beyond the recommended doses that unintentionally leave residues that pose a variety of human and ecological health threats (Md Meftaul et al., 2020).

Water-quality samples were collected from 32 streams within the Potomac River Watershed during low-flow conditions to represent periods with the greatest effects from ACCWW and legacy pesticide sources. In the study watersheds,  turfgrass percentage of drainage area was found to be significantly correlated with all target fungicides, insecticides, and diuron. This study did not assess variability in results over time, which may be important at some sites based on local conditions. At best this model could be used as a screening tool and not much more.