Climate Change or Weather

Last summer it was extremely hot and dry here in Prince William County, Virginia. It was the year my heat pump failed, others had wells go dry and the Interstate Commission on the Potomac River Basin (ICPRB) engaged a study for various climate scenarios of water supply availability from Potomac Watershed to determine if the water supply would be adequate to serve the population. This year is a different story. The summer has been cooler and wetter. Drought here is a distant memory. The summer is ending with only a couple of weeks this summer above 90 degrees and no days in triple digits and my garden is green.

The climate of the earth is constantly changing and the oceans rising for 10,000 years. Scientific studies and computer models have indicated that over the past century the earth has warmed 1.3°C. This warming is not particularly alarming in itself given our planetary history, but the speed of this temperature increase and the fact that the warming is projected to continue at an accelerated pace due to carbon dioxide concentrations in the atmosphere is worrisome. The planetary warming is forecast to cause sea levels to rise at an accelerated rate due to melting of sea ice in parts of the world, and changes in weather and patterns and precipitation. If carbon dioxide (CO2) concentrations in the atmosphere are the driving force in earth’s temperature the some portion of the weather extremes recently experienced are being caused by man.

According to the report “Explaining Extreme Events of 2012 from a Climate Perspective” released this week by the Bulletin of the American Meteorological Society, some of the extreme weather events of last year had mankind as one of the causes. Overall, 18 different research teams from around the world worked on the peer-reviewed report that examined the causes of 12 extreme weather events that occurred on five continents and in the Arctic during 2012. Hurricane Sandy slammed into the U.S. mid-Atlantic seaboard on October 29–30, 2012 causing widespread damage and devastating disruption to critical infrastructure. Hurricane Sandy broke 16 historical storm-tide levels along the East Coast though Sandy’s magnitude on the Saffir-Simpson hurricane wind scale was not particularly large; its westward strike heading was very unusual and it struck at high tide. Since 1851, nine other hurricanes (Category 1 and 2) have made landfall with similar proximity but all were heading north-northeastward. It was concluded that climate changes caused by man had no significant impact on that storm or the damage it caused . ($60.2 billion has been allocated by Congress to fund repair and mitigation measures.) However, the authors note that in the future rising sea levels could make smaller storms more likely to cause devastating damage.

Likewise, human-induced climate change was found to have had little impact on the lack of precipitation in the central United States in 2012 and continues in the current drought. However, in the section of the report titled, The Extreme March–May 2012 Warm Anomaly Over the Eastern United States by Thomas R. Knutson, Fanrong Zeng, and Andrew T. Wittenberg the authors found Approximately 35 %t of the extreme warmth experienced in the eastern U.S. between March and May 2012 can be attributed to human-induced climate change; and say high temperatures are now likely to occur four times as frequently due to human-induced climate change.

However the forecast is sensitive to the base period used and our assumptions of weather variability. The near-record Atlantic Ocean warmth off the east coast of the United States during March to May 2012 was annualized using a “multistep attribution” approach from Hegerl et al. (2009). This involves an assessment that attributes the observed change in seasonal mean temperature extremes to a change in climate and a separate assessment that attribute the change in climate and/or environmental conditions to external drivers and external factors. The observed trends in the figure below indicate that (according to the model-generated variability) the measured temperature extreme in 2012 were inconsistent with internal climate variability alone.

from Knutson et al

This was determined by using a control period of weather as a surrogate for the possible natural variability of temperatures. Since the heat wave of March-May 2012 occurred in a region with what the authors call “detectable long-term anthropogenic warming,” they concluded that anthropogenic forcing also likely contributed significantly to the observed temperatures in 2012. They state that a rough estimate of the anthropogenic contribution would be about 35% (based on the modeled value of ~1.3°C and the 2012 observed temperature anomaly of ~3.7°C). This 3.7°C event was 2.8 times stronger than the expected 1.3°C due to anthropogenic forcing in 2012. So, according to the authors weather variability played a substantial role.

The authors have simply assumed the 1.3°C portion of the anomaly is due to anthropogenic forcing as predicted by previous modeling of the climate. The estimate of the contribution of anthropogenic forcing to the observed weather variability are sensitive to two assumptions, the accuracy of 1.3°C increase in global temperatures numbers produced by models and the baseline period assumed by the authors. Here they used the period 1881–1920 as the baseline; if they used 1861–2012 as the baseline period, the risk of the event increases by about a factor of 5 rather than 12, and the portion of the temperature anomaly attributed to anthropogenic forcing would be 22%. If the average temperature increase were due to man were assumed to be lower, then the contribution of anthropogenic forcing would be less and vice versa.

The accuracy of climate models to regional variability is unclear. On a whole earth basis the climate models show at this point there is nothing that we can do to stop global warming and climate change. What is going to happen will happen.

Slowing the Erosion from Rising Sea Level and Storms

Breakwater at Westmoreland State Park

At the quarterly meeting of the Potomac Watershed Roundtable Scott Hardaway from the Virginia Institute of Marine Sciences at William and Mary and Mike Vanlandingham the last standing Shoreline Engineer from the Virginia Department of Environmental Quality (DEQ) spoke about shoreline erosion and stabilization in general and along the Potomac River, talking about the problem and potential solutions for slowing the natural forces that are eroding our shorelines. Since 1980 the DEQ has provided Shoreline Erosion Advisory Service to provide technical assistance in the form of an advisory report and plan reviews to landowners, state owned land, localities, and federal agencies experiencing tidal erosion along the 5,000 miles of tidal shoreline in Virginia.

Approximately 15,000 years ago the ocean coast was about 60 miles east of its present location, and sea level was about 300 feet lower. At that time there was no Chesapeake Bay. Instead there was a river that meandered out to sea. It is that ancient river that created the deep channel within the Bay and estuary waters. Sea level continues to rise in the Chesapeake Bay, it was estimated by Scott Hardaway to be rising at about a foot per century, and others have estimated that this rise will accelerate in the future. The rising sea level is one of two primary causes of shoreline erosion, the other is wave action. Storm events can cause powerful waves and change the shape of the shoreline as they erode and transport soil and sand from one part of the shore to another.

The factors that influences the way that the shore line will erode are; coastal geology, the amount of open water, existing shore conditions, storm surges, and rising sea level. While the erosion can be managed, it cannot be stopped. Rising sea level and storm waves are relentless forces. The erosion of shoreline in Virginia has been complicated by the rapid and extensive development in these areas in the past 25 years. The development changes the nature of the shore and creates difficulties in trying to implement an area strategy with multiple property owners who cannot or will not take the (decades) long term view. There are basically three strategies that can be implemented for fighting shoreline erosion: soft, hard and combination. There is little that can be done to permanently hold back the rise in sea level; however shoreline management strategies can be used to blunt the destruction of storm related wave action.

A soft strategy is utilizing wide fringing marshes, beaches and dunes to absorb the energy of waves and reduce the effects that storms will have on adjacent upland banks. With an adequate marsh fringe, beach or dune protection upland banks may only be impacted by the most severe events- at least for a while. Nonetheless, over time, marshes and beaches are eroded themselves and can no longer protect the shore and according to Mr. Vanlandingham, there are areas where a massive storm can erode 30 feet of shoreline in a single year though the shoreline overall averages a loss of 1 foot per year. As rising sea level and erosion narrow beaches and marshes over time, the upland banks are become impacted by storm surge which causes bank instability. Continual erosion can result in sudden collapse of an upland bank taking yards, decks, homes and roads.

Hard strategies to shoreline protection are riprap revetments, retaining walls with anchor systems and bulkheads. The combination strategies utilize groins in combination with the bulkheads and breakwaters. Bulkheads, revetments, and groins are the most common protection strategies currently employed to protect shorelines from erosion. Bulkhead and seawall are often used to describe the same thing, but there really is a difference: bulkheads are generally smaller and less expensive than seawalls. Bulkheads are usually made of wood. They are designed to retain upland soils and often provide minimal protection from severe storms. Seawalls are generally made of poured concrete and are designed to withstand the full force of waves.

In recent years, rock or riprap revetments became more widely used to protect shorelines. A properly designed and constructed rock revetment can last fifty years or more because it can be maintained by the addition of more stones. The revetments have sloped and rough stone faces that decrease wave reflection and bottom scour. Revetments need to be built high enough to withstand waves during extreme storms or they will not work. In addition, the banks need to be graded to create a stable slope.

Between the 1950s and 1980s, groins were a popular way to trap sand and build a modest beach area and are widely seen in beach communities. A groin is a wood structure perpendicular to the shoreline designed to “catch” sand and prevent erosion of the beach. On a relatively wide sand beach the sand will accumulate on the up drift side of a groin. If enough sand were available, the shoreline banks would gain some degree of protection from erosion. However, the sand capture by the groin will prevent the sand from reaching down drift areas increasing erosion there and can create difficulties and lawsuits amongst property owners. Breakwaters can work as a better strategy if used along a long span of shoreline. Breakwaters are built offshore to control shoreline erosion by maintaining a wide, protective beach.

The breakwater, sitting out perpendicular to the shore, “breaks” the force of the waves and dissipates the energy so the waves do not erode the beach or upland banks. Unlike groins that merely capture sand. Breakwater systems are designed to create stable beaches and allow various species of marsh grasses to be established at the site.

from Hardaway

In the past decade or so, coastal engineers use combinations of hard and soft structures in storm damage reduction design. A rock seawall buried within a dune was constructed in 2000 in Virginia Beach, Virginia by the Army Corps of Engineers to protect critical naval infrastructure. Such approaches have been adopted because they proved to be both cost-effective and environmentally friendly alternatives to more classical coastal structure design. Yet, because of the rarity of extreme flood and wave events, these multi-level designs have not been demonstrated to be effective as clearly as they were in New Jersey during Hurricane Sandy in October 2012 when the fate of two adjacent communities demonstrated the effectiveness of a rock seawall buried within a dune.

Hurricane Sandy devastated the Jersey shoreline destroying many coastal communities, caused widespread erosion of the sand dunes as well as having the Barrier Island breached in some locations. Along the hardest-hit stretch of the New Jersey shore are two adjacent coastal communities: the Boroughs of Bay Head and Mantoloking. Before Hurricane Sandy, these adjacent boroughs featured similar topography and residential development. Yet, while similar surges and large waves arrived at their shores, the communities experienced vastly different levels of destruction. A team of scientists lead by Jennifer L. Irish, associate professor of civil and environmental engineering in the College of Engineering at Virginia Tech investigated the shoreline immediately after the storm, and recently published their findings.

From J.L. Irish Buried Seawall

The cause of difference in damage between the two communities turned out to be a long forgotten sea wall originally built in 1882 that had formed the core of the Bay Head dune very much like the structure installed at Virginia Beach. The stone seawall had been covered over with fine dune sand by Aeolian transport and beach nourishment during the twentieth century and forgotten. While similar surges and large waves arrived at both towns the amount of damage and erosion was vastly different between the two. In Mantoloking the dune structure was entirely sand and their entire sand dune was destroyed by the storm. Water washed over the barrier spit and opened three breaches hundreds of feet wide and the sand was swept away by the waves. In Bay Head, only the portion of the dune located seaward of the seawall was eroded and the section of dune behind the seawall received only minor local scouring. The dune remained in place and the sand remained on the beach. In addition in Bay Head only one oceanfront home was destroyed. In Mantoloking, more than half of the oceanfront homes were classified as damaged or destroyed.

The discovery of the relic seawall came as a surprise to many of the residents, generations of families do not stay in communities and there is little realistic long term planning for future storms and rising sea levels. This relic seawall and the deposited dune sand combined to form a combination soft and hard structure that is now in use to protect the shoreline. This design was discovered as the effective protector of the Bay Head shoreline and demonstrated to work during the “Superstorm.”

Shoreline protection strategies continue to evolve. In many locations, elevated shoreline stabilization structures are combined with beach nourishment for shoreline protection. Nontraditional technologies (beach drains, geotextile bags, artificial breakwater structures, wetlands, etc.) are also being investigated in field experiments. Nonetheless, man cannot hold off the rising seas forever. First we protect the shore with engineered barriers (of all types), then we rebuild the beaches by adding sand and marshes. Ultimately we will have to accommodate the rising sea level by raising structures and retreating from the shore.

The Flood Waters in New York

Hurricane Sandy passed through Virginia slamming the Eastern Shore with tide surges of up to 7 feet breaching the sand dunes and flooding towns all along the Eastern Shore, from Cape Charles to Chincoteague. Here in the eastern Piedmont the hurricane brought winds and rains, knocking out power, a bad storm and nothing more. I was born in New York and spent a large part of my youth there so last week we stayed planted in front of the TV watching the storm’s progress (powered by our generator) on the Weather Channel and of all stations CNBC which had some of the most up to date New York and New Jersey images. The winds and rain took down a few trees in our yard, ripped branches from others and several of my plum trees were blown part way out of the ground and needed to be staked. A few shingles were blown off the roof. The winds and rain battered the house and garden, but Sandy pretty much missed us and five guys with chain saws and shovels have pretty much brought the garden back to normal. My cousin in the Five Towns found a hot spot in a Verizon store to send me an email saying “Atlantic Beach, Long Beach are destroyed. People have boats in their yard that before the storm were at least two blocks away in the water. Cars are ruined, houses have water and fish swimming inside! Nerves are unraveling all around us. Getting gas for the car was at least an hour wait. By the way all of the talk about a quick response.......no one has seen FEMA and not much has improved except some local power has been restored.”

Super Storm Sandy made landfall near Atlantic City taking down the famed boardwalk, the winds and high tide left death, destruction and flooding in her wake. The flood waters have receded and power is being restored. So the big cleanup begins. Floodwaters can contain a wide number of toxins and pathogens in the older cities like New York, areas of Long Island and New Jersey and Baltimore. Chemicals long forgotten layered in underground NYC- oil residues containing metals and electrical insulating fluids from long ago, storm water carrying oils and grease from cars and machinery, gas stations, solvents from dry cleaners. Pesticides, solvents, paints and other products stored in flooded areas may also find their way into the waters. Most importantly the combined sewer systems of New York and New Jersey were unable to handle flows and power to treat sewage was in many places was knocked out. The floodwaters contain a mix of excess stormwater and untreated sewage. The floodwaters can be over 99% water and sight or smell alone is not enough to judge water quality. Coliform bacteria which include E. coli (Escherichia coli) or fecal coliform types that indicate contamination by animal manure or sewage can be impossible to detect by taste or smell. However such waters may contain one or more of a variety of potentially pathogenic microorganisms such as Salmonella, Shigella, enteric viruses, Giardia or Cryptosporidium that may be present in human or animal manure and can cause severe illness.  

Few would think of drinking the dirty flood waters, most drinking water sources in the New York/ New Jersey area are safe. Wading through the standing water, working in it to clean up the destruction from Sandy, or walking through or playing in streets full of standing water can risk contracting a skin rash or water-borne illness from pathogenic microorganisms. It is important to protect your health and your children in this long crisis period. Children are especially susceptible to illness. My cousin was in that Verizon store keeping her grandsons busy and out of trouble. FEMA (Federal Emergency Management Agency) posted the following tips gathered from their storm and flooding experience to keep children safe.

Parents or other caregivers should directly supervise children - this prevents them from playing in or around floodwaters. It doesn't take long and it doesn't take much water for children to drown and remember that the water potentially contains contaminants.

Watch for live wires or power sources - electricity from streetlights and downed power lines may be active and may cause a deadly shock through contact with standing water or direct contact with live lines especially as power is being restored.

Keep children from playing around drainage ditches, storm drains, river channels, or any place with moving/standing water - children can fall in, get stuck, or drown.

Be aware of what’s in the water - standing or flood waters can be contaminated and cause children to become sick. Playing in water could also result in being bitten by rodents or other wildlife.

As the storm waters recede it is possible to begin the cleanup. The New York City Department of Environmental Protection has temporarily suspender permitting requirements for businesses and homeowners seeking to discharge water from flooded properties into the City’s sewer system.New York City Department of Environmental Protection (DEP) provided Water-On-the-Go drinking fountains with free portable water to six Manhattan locations with high incidence of power failure as well as to the Rockaways. Water-On-the-Go will serve residents in these areas from 9:00 A.M. to 5:00 P.M. daily until power is restored to these areas. My other cousin in uptown Manhattan made it through entirely unscathed and never lost power. She tells me that the coffee shops were very crowed and many restaurants were closed, Manhattan is entirely dependent on deliveries over bridges and through tunnels and none were coming in.

New York City drinking water remains safe to drink for most areas. Since the start of Hurricane Sandy, the DEP has performed thousands of tests on drinking water samples from throughout the city and continues to monitor water quality. The city has set up mobile phone charging stations, so that those with smart phones can stay in touch and get information from FEMA and NY State and City websites as the cell phone companies restore service. Resourceful New Yorkers have found coffee shops in uptown with electricity, Wi-Fi and water and in stores on Long Island. In many flooded areas of the city that remain without water and power many will not leave their homes for shelters-they are afraid of sleeping in a shelter and of what will happen to their homes while they are gone. Neither their person nor their property is safe without their constant vigilance. 

Storm Prep and Cleanup for Well and Septic Owners

With tropical storm Sandy approaching the east coast and potentially heading for Virginia and much of the mid-Atlantic and northeast, the Governors along the eastern seaboard have declared states of emergency. The local utilities have already requested additional workers to restore power lines, so it seems a good time to discuss basic storm preparations for your home and how intense rainfall associated with tropical storms and hurricanes can impact your drinking water well and septic system, and what you should do if your well and septic system are impacted. I am posting this blog entry a little early, so I can run off to the grocery store and pick up some more milk, orange juice, coffee and produce and any other emergency supplies I don’t have on hand.  

My home is on well water and without electricity I have no water, no septic, no sump pumps, my freezer containing a quarter of a cow (grass fed) that is in danger of spoiling, and my life generally disrupted with the loss of the all the modern conveniences. So five years ago, I had a Guardian 16 kilowatt automatic generator manufactured by Generac installed. When the power to the house is cut, the generator automatically kicks in to power most of the house in about 20 seconds. The generator runs on liquid propane from a tank buried in my yard that also powers my hot water heater, furnace, gas grill and stove. The generator can supply the house for more than two weeks depending on whether the gas furnace is running, and is housed in an insulated aluminum casing under my deck (muffling the sound) and looking good as new even after five years of sitting outside.

My Generator

The generator was serviced over the summer after the last storm and was filled with oil, and the propane tank was filled last week in preparation for winter. (Note that if the generator runs more than a few days especially when new it will need oil.) So, I am all set to go on those fronts. However, it is a little late to be installing a whole house generator and I understand that there has been quite the run on portable generators, so you may not be able to get one today. So, you need to make sure that your sump pump or pumps are operational and have battery backup (check those batteries and make sure they work), clear all the leaves out of your gutters and make sure the down spouts drain away from your foundation. Keeping water away from the house will protect your home and minimize the work that the sump pumps will have to do. Make sure you have batteries and flash lights. Even with the generator, we keep flashlights around. If you do not have a generator, fill plastic bags with water and put as many as you can in your freezer today. The water will freeze by tomorrow and the frozen water will serve to keep the freezer cold without power- just like a cooler.  If the power goes out, you might also want to use some of the ice bags to keep your refrigerator cold. In the end you can drink the water. Bring in all outdoor furniture, decorations, garbage cans and anything else that is not tied down, put them in the garage-that includes the pumpkins on the stoop.

Without electricity your well pump will not work, so you will need to fill the bathtubs and gallon jugs with drinking water when the storm hits to make sure that you will have water. If your home and well are on low ground, and the area floods then it is possible your well could be impacted. After a storm, brownish or dirty water coming from the well is a common occurrence and indicates surface water infiltration carrying dirt and contaminants into the well. If your well was flooded or your water appears dirty or brownish you need to clear your well and disinfect it and the stored water may have to last you a few days.

Septic systems should not be used immediately after flooding. Drain fields will not work until underground water has receded. Septic lines have been known to break during significant flooding, so keep an eye out for that. Whenever the water table is high or your septic drain field has been flooded, there is a risk that sewage will back up into your home. The only way to prevent this backup is to relieve pressure on the system by using it less. Basically, there is nothing you can do but wait it out, do not use the system if the soil is saturated and flooded. The wastewater will not be treated and will become a source of pollution, if it does not back up into your house, it will bubble up into your yard. Conserve water as much as possible while the system restores itself the drain field dries out and the water table fails. Also, if the septic system is not and entirely gravity system you will need power to run the pumps and need to understand if there is adequate gravity flow to move the sewage from the house.

The available volume in the septic tank (assuming you occasionally pump it) should give you several days of storage and water use if you conserve water to allow your drain field to recover. The biggest single use of water in the home is laundry- a top loading washer uses 52 gallons and a front load washer uses 27 gallons- do not do laundry until the system has dried out.  Toilets manufactured before 1992 use 5 or more gallons per flush while newer, low flush toilets use 1.5 gallons per flush. Only flush older toilets when you have to- not for urine. Go easy on your water use. The septic system operates on the principals of settling, bacterial digestion, and soil filtration all gentle and slow natural processes that will have been battered by the storm. Do not pump the septic tank while the soil is still saturated. Pumping out a tank that is in very saturated soils may cause it to “pop out” of the ground. Recently installed systems may “pop out” of the ground more readily than older systems because the soil has not had enough time to settle and compact.

If your well was flooded or your water appears dirty or brownish after the storm you need to clear your well and disinfect it. Your power must be restored to disinfect the well. Run your hoses (away from your septic system and down slope from your well) to clear the well. Run it for an hour or so and see if it runs clear. If you have a robust recharge rate as I do it will take hours to clear the well. If not let the well rest for 8-12 hours and run the hoses again. Several cycles should clear the well. What we are doing is pumping out any infiltration in the well area and letting the groundwater carry any contamination away from your well. In all likelihood the well will clear of obvious discoloration. Then, you need to disinfect your well. This is an emergency procedure that will kill any bacteria for 7 to 10 days.

Well with a sanitary cap

Determine what type of well you have and how to pour the bleach into the well. Some wells have a sanitary seal which must be unbolted. Some well caps have an air vent or a plug that can be removed. On bored or dug well, the entire cover can simply be lifted off to provide a space for pouring the bleach into the well. Carefully pour the bleach down into the well casing using a funnel if necessary. For a typical 6 inch diameter well you need 2 cups of regular laundry bleach for each 100 foot of well depth to achieve about 200 parts per million chlorine concentration. If you don’t know the depth of the well, pour a half gallon down the well. Wear rubber gloves, old clothes and protective glasses to protect you from the inevitable splashes, and don't forget a bucket of bleach mixed with water to wash the well cap.

After the bleach has been added, run water from an outside hose into the well casing until you smell chlorine coming from the hose (depending on the depth of your well and the recharge rate, this can take an hour or more). This step is important to mix the chlorine in the well. Then turn off the outside hose. Now go into the house and if you have a water treatment system, switch it to bypass before turning on the indoor faucets, then one bathroom and sink at a time, turn on the cold water faucets until the chlorine odor is detected in each faucet, then shut it off and move on to the next sink, or bathroom (if you have an automatic ice maker turn it off and dump the ice. Do not turn on the hot water. Once the inside system has been done, go back to the outside spigots and run the hoses until you smell chlorine coming out. Warning if you have iron bacteria in your well, your water may turn completely rust colored. Do not panic it will flush out of the system, but do not use the hot water until the water runs clear or you will have to drain the hot water tank to prevent staining.

Wait 8 to 24 hours before using the water. You want to run the hoses until the water runs clear if you have iron bacteria or simply run the hoses to prevent killing all the bacteria in the septic system. It is important not to drink, cook, bath or wash with this water during the time period it contains high amounts of chlorine whose by products are a carcinogen. After at least 8 hours, run the water into a safe area where it will not kill your lawn, your trees or plants pollute lakes, streams or septic tanks. Run the water until there is no longer a chlorine odor. Turn the water off. The system should now be disinfected, and you can now use the water for 7 to 10 days when the effects of the disinfection wear off. After 7 to 10 days you need to test your well for bacteria to make sure that it is safe.

The Virginia Cooperative Extension (VCE) Office will be hosting a drinking water clinic for well owners in Prince William County as part of the Virginia Household Water Quality Program and subsidizing the analysis cost. So you may want to attend to test your well. The Kickoff Meeting will be on November 5, 2012 at 7 - 8:30 pm at the Old Courthouse, 9248 Lee Avenue in Manassas, VA 20110. Unlike public water systems, private systems are entirely unregulated; consequently, the well testing, and treatment are the voluntary responsibility of the homeowner.