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Is Texas Water Really Protected?

architecture-buildings-city-45182.jpg

Texas industries are regularly in violation of environmental laws. They dump human waste and chemicals into its water bodies. Unfortunately, without facing consequences. Environment Texas, in a recent report, shows that over half of the Industrial facilities from Texas are in violation of their wastewater permits.

Along with human waste, the facilities dump grease, oil, and a number of miscellaneous chemicals into state rivers and bays. This evaluation of water affairs doubts the effort by Texas Commision on Environmental Quality (TCEQ) to protect Texan waters. The report underscores the fact that TCEQ is lax and its efforts are insufficient.  

In their report, Environment Texas states that 132 of the 269 Industrial facilities from Texas violate their wastewater permits. One of them is the Ineos plant which creates polymers for pharmaceuticals and pipes. Researchers pointed out that the violation count is 938 across 21 months between 2016-17. This makes Texas a state with the highest number of violations in the USA.

 

In about 300 of these violations, refineries, chemical companies, and wastewater treatment plants dumped waste into rivers, bays, and lakes which were previously classified as ‘impaired’ by the EPA.  An example of this is the Neches River. Even after the EPA classified it as ‘impaired’, it is one of the common sites for toxic waste and pollutants to be released. Today, the Neches is one of the dirtiest in the country. This further delays the water’s recovery process and harms aquatic life.

 

Luke Metzger, the executive director of Environment Texas says that TCEQ is lax and thus, facilities are not forced to comply with these permits.

The Ineos USA facility holds a repeated violation (8 times) of dumping wastewater into the Chocolate Bayou between Jan. 2016 and Sept. 2017. Their wastewater release contained a large proportion of the E. Coli bacteria which points toward fecal matter dumping. The facility has failed to comply with the Clean Water Act for 12 months over 3 years. In spite of the obvious violations, TCEQ did not issue fines.

In February 2018, the Observer reported an investigation on the biased level of enforcement by the TCEQ. According to the report, there is a disparity between how TCEQ penalizes large corporate polluters and small businesses. Large corporate polluters (refineries & petrochemical plants) are rarely penalized for air contamination and illegal pollutant release even though they have the resources to pay, make amends, and fight back. Whereas, small gas stations were fined thousands of dollars for relatively simpler violations such as recordkeeping. Environment Texas, in a recent report, highlights this partiality where corporate giants easily get away with water pollution and small businesses are financially choked.

TCEQ’s spokesperson, Andrea Morrow, says that they routinely monitor the data which companies submit for violations. The companies also report permit exceedances which they check. She says that the TCEQ penalizes and has the authority to enforce corrective measures to improve compliance when violations are grave and warrant formal action.

The report clearly hints lax enforcement by the TCEQ. It highlights poor accountability for repeat violators (the corporate offenders). Because legal and procedural affairs take time (months to years), it is uncertain if TCEQ will penalize violators with a fine in some cases. Metzger believes that it is unlikely that these facilities would face consequences due to TCEQ’s lax track record.

In 1972, the Clean Water Act became a federal law after the Cuyahoga River (Ohio) caught fire. This seminal law created a nation-wide vision of a country with zero pollutant discharge in waterways over the next 13 years. Unfortunately, and at a high cost, this vision is far from being realized.

Regions hosting heavy industrial activities had more polluters than the industrially less dense regions. About 600 of the 938 violation cases involved facilities from Harris, Jefferson, and Nueces counties where the state’s largest industrial operations are run.

Without giving any undue justification, Texas does have a high number of facilities which in turn create the opportunity for pollution. Although this increases the likelihood of pollution, it does not warrant repeated violation of permits. Texas, today, has the highest pollution rank.

As per the report, federal enforcement has decreased under Trump’s administration. Fines have lowered and the EPA is pursuing fewer cases. The monetary value of fines was 60% lesser in the first 6 months of Trump’s administration as compared to Obama’s, or Bush’s, or Clinton’s.

To compound these issues, the current administration has proposed a reduction in EPA’s civil enforcement budget. The budget is likely to drop by $30.4 million for the year 2019. The auxiliary federal budget which funds grants that assist states in fighting water pollution will drop by 20% in 2018 and 2019.

Interested in learning more about wastewater treatment options that can help alleviate many of these problems? Contact us today. 

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Understanding Gypsy Moth Outbreaks

gypsy moths on tree
Photo: Tom Worthley

Gypsy moths (also known as the North American Gypsy Moth or the European Gypsy Moth) were imported to North America from Eurasia in 1869 for a silk production experiment. They have caused periodic defoliations in New England since then and particularly severe defoliations in the early 1980s and again in Connecticut and Massachusetts in 2016 and 2017. (Gypsy moths do not build webs – the webs you see in cherry trees are tent caterpillars.)

Female moths lay between 500 and 1,000 eggs that overwinter until spring when they hatch. Eggs are usually found underneath the bark scales of trees, on trunks, branches or other protected sites. Eggs last for 8-9 months before they hatch. Adults only live for about one week while they mate and lay eggs. Gypsy moth populations can persist with very low numbers for years but under the right conditions can have outbreak years where populations explode.

The caterpillars feed on leaves of most deciduous trees and many conifers as well. After feeding for some time they descend to the ground by means of silk threads to change size (molt). Silk threads and numerous hairs on the bodies of small, early-instar (stage) caterpillars allow them to be spread by the wind. These caterpillars change size three times before entering the pupal stage and maturity.

Gypsy moths only damage trees during the larval (caterpillar) stage when they are feeding on the leaves, and leaf-feeding and defoliation is the only type of damage they do. In high numbers they can completely defoliate the trees. One gypsy moth caterpillar can eat as much as eleven square feet of leaf area.

Most deciduous trees have the ability to re-set buds and produce a second set of leaves following defoliation.

dead caterpillars on tree
Photo: Tom Worthley

Coniferous trees do not have this ability. Multiple defoliations can be problematic for the trees. Gypsy moth caterpillars will feed on most tree and shrub species (500 total species!) but prefer oak and beech. Tulip trees (yellow poplar) are not affected. Pines and hemlocks are likely to die after one defoliation.

Multiple defoliations combined with drought are causing individual tree and stand-level mortality in some areas. Trees that have not “leafed-out” in 2018 can be seen in numerous locations around the state. In some places, large individual roadside trees and trees near structures that have died present potential future safety hazards. In forest stands on state and private forest lands, sufficient oak mortality can be observed to warrant consideration of forest harvesting activities to salvage timber value. Private woodland owners are well advised to consult with a CT-Certified Forester to evaluate their woodland conditions. (Links provided below.)

Since the 1980s, a fungus from Japan, Entomophaga maimaiga, has been keeping gypsy moth populations under control but during dry conditions the fungus is less active. Gypsy moth populations seem to explode when there are dry conditions during the spring and summer months.

Natural controls include:

  • Birds (limited effectiveness, small instars only)
  • Vertebrates (deer mice and shrews)
  • Invertebrates (ants and ground beetles, parasitic flies and wasps)
  • Viral Disease Wilt
  • Pathogens like Entomophaga maimaiga fungus

There are a few management tools available:

  • Bacteria-based treatments exists.
  • Soapy water sprays (horticulture soap/oils mixed with water).
  • Traps to catch adults.
  • Finding and destroying egg masses (too late for 2018).

Pesticides are not commonly used because of chemical toxicity and are impractical for entire forests. If used for an individual tree be sure to read the label.

On the UConn campus in Storrs the arborist crew will spray some campus trees using bio-based spray. Trees that don’t leaf out will be removed. Some salvage of dead trees in the UConn Forest will take place as appropriate for fuel wood and saw logs. Inspections will be done in early summer.

A Certified Forester should be consulted for stand-level management and a licensed arborist for individual trees near homes and buildings. More information is available from the Department of Energy and Environmental Protection: http://www.ct.gov/deep/cwp/view.asp?a=2697&q=589362&deepNav_GID=163 and the Connecticut Agricultural Experiment Station; http://www.ct.gov/caes/site/default.asp .

To find an arborist link to the CT Tree Protective Association, www.ctpa.org.

Article by Tom Worthley

[Read More …]

Understanding Gypsy Moth Outbreaks

gypsy moths on tree
Photo: Tom Worthley

Gypsy moths (also known as the North American Gypsy Moth or the European Gypsy Moth) were imported to North America from Eurasia in 1869 for a silk production experiment. They have caused periodic defoliations in New England since then and particularly severe defoliations in the early 1980s and again in Connecticut and Massachusetts in 2016 and 2017. (Gypsy moths do not build webs – the webs you see in cherry trees are tent caterpillars.)

Female moths lay between 500 and 1,000 eggs that overwinter until spring when they hatch. Eggs are usually found underneath the bark scales of trees, on trunks, branches or other protected sites. Eggs last for 8-9 months before they hatch. Adults only live for about one week while they mate and lay eggs. Gypsy moth populations can persist with very low numbers for years but under the right conditions can have outbreak years where populations explode.

The caterpillars feed on leaves of most deciduous trees and many conifers as well. After feeding for some time they descend to the ground by means of silk threads to change size (molt). Silk threads and numerous hairs on the bodies of small, early-instar (stage) caterpillars allow them to be spread by the wind. These caterpillars change size three times before entering the pupal stage and maturity.

Gypsy moths only damage trees during the larval (caterpillar) stage when they are feeding on the leaves, and leaf-feeding and defoliation is the only type of damage they do. In high numbers they can completely defoliate the trees. One gypsy moth caterpillar can eat as much as eleven square feet of leaf area.

Most deciduous trees have the ability to re-set buds and produce a second set of leaves following defoliation.

dead caterpillars on tree
Photo: Tom Worthley

Coniferous trees do not have this ability. Multiple defoliations can be problematic for the trees. Gypsy moth caterpillars will feed on most tree and shrub species (500 total species!) but prefer oak and beech. Tulip trees (yellow poplar) are not affected. Pines and hemlocks are likely to die after one defoliation.

Multiple defoliations combined with drought are causing individual tree and stand-level mortality in some areas. Trees that have not “leafed-out” in 2018 can be seen in numerous locations around the state. In some places, large individual roadside trees and trees near structures that have died present potential future safety hazards. In forest stands on state and private forest lands, sufficient oak mortality can be observed to warrant consideration of forest harvesting activities to salvage timber value. Private woodland owners are well advised to consult with a CT-Certified Forester to evaluate their woodland conditions. (Links provided below.)

Since the 1980s, a fungus from Japan, Entomophaga maimaiga, has been keeping gypsy moth populations under control but during dry conditions the fungus is less active. Gypsy moth populations seem to explode when there are dry conditions during the spring and summer months.

Natural controls include:

  • Birds (limited effectiveness, small instars only)
  • Vertebrates (deer mice and shrews)
  • Invertebrates (ants and ground beetles, parasitic flies and wasps)
  • Viral Disease Wilt
  • Pathogens like Entomophaga maimaiga fungus

There are a few management tools available:

  • Bacteria-based treatments exists.
  • Soapy water sprays (horticulture soap/oils mixed with water).
  • Traps to catch adults.
  • Finding and destroying egg masses (too late for 2018).

Pesticides are not commonly used because of chemical toxicity and are impractical for entire forests. If used for an individual tree be sure to read the label.

On the UConn campus in Storrs the arborist crew will spray some campus trees using bio-based spray. Trees that don’t leaf out will be removed. Some salvage of dead trees in the UConn Forest will take place as appropriate for fuel wood and saw logs. Inspections will be done in early summer.

A Certified Forester should be consulted for stand-level management and a licensed arborist for individual trees near homes and buildings. More information is available from the Department of Energy and Environmental Protection: http://www.ct.gov/deep/cwp/view.asp?a=2697&q=589362&deepNav_GID=163 and the Connecticut Agricultural Experiment Station; http://www.ct.gov/caes/site/default.asp .

To find an arborist link to the CT Tree Protective Association, www.ctpa.org.

Article by Tom Worthley

[Read More …]

Is there any hope to fix our salt problem? Perhaps…

Another winter has finally ended, and messy roads and salty cars are quickly becoming a distant memory. Where did all that salt go? The millions of tons of deicing salts that get applied to our roads either wash off into local streams, or move into the local groundwater. Yet another research study has recently come out documenting the harmful effects this salt is having in the environment (see UConn Today article). Salt impacts aquatic life in streams, vegetation, and drinking water wells, creating a human health concern. Unfortunately there is no good cost-effective alternative available at this point.

Faced with this situation, New Hampshire decided to attack this problem at the source: reduce how much salt is being applied to the landscape. The Green SnowPro certification program provides municipal public works staff and private contractors with training on how to more efficiently apply deicing salts while still keeping the roads safe for travel. Information is provided on how salt actually works, what the impacts are on the environment, how to calibrate equipment, how much salt to apply given the weather conditions, and how to use anti-icing strategies. Another benefit of the program is that businesses who hire certified applicators receive reduced liability from damages arising from snow and ice conditions, creating an incentive for businesses to hire trained contractors. The New Hampshire Department of Environmental Services has reported that the program is helping to reduce salt application across the state.

Given the recent success of the program in New Hampshire, the program is being adapted here in Connecticut. UConn’s Tech Transfer Center has partnered with CT DOT, DEEP, and UConn CLEAR to pilot the program for municipal public works staff. The pilot session will be later this summer- check the T2 website for details. The goal is to expand the program to private contractors, just as New Hampshire has done.

Although our salt problem will not be fixed overnight, programs like this offer the best hope to tackle this very serious problem.

By Mike Dietz

Originally posted on CLEAR.UConn.edu

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Reducing Costs and Improving Water

UConn campus in the snow
A snowy view of North Eagleville Road on Jan. 30, 2018 showing renovovations including a new median, expanded sidewalk and stone wall. (Peter Morenus/UConn Photo)

Michael Dietz from UConn Extension/CLEAR worked with the Tech Transfer Center at UConn to provide a winter operations training for UConn facilities staff. As a result of the training, salt applications were reduced by 3,600,000 pounds, improving water quality, and saving UConn roughly $200,000. Thanks to the UConn winter operations staff and the Tech Transfer Center for helping to make this happen.

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Controlling Ticks

deer tickThe Centers for Disease Control and Prevention (CDC) recommends creating a tick-safe zone. Ticks feed on blood of animals including humans. Tactics to reduce the attractiveness of animals traveling into your yard will keep the number of ticks dropping off of them reduced. Do not feed the birds as chipmunks, squirrels and many other animals visit to eat fallen seeds. Remove leaf litter as a hiding place for small animals and ticks. Clear tall grass and brush from edges of turf and around home. Keep lawn mowed. Keep any wood piles dry and neatly stacked to discourage rodents from using it as a home. Do not place patio or play areas near wooded areas where animals and ticks will be living. Use fencing to keep out deer and larger animals from the yard. Create a 3-foot wide barrier of gravel or wood chips between lawns and woods to stop ticks from entering the lawn. Ticks do not like to cross hot, dry expanses.

Chemical control includes the active ingredient bifenthrin or carbaryl or permethrin or pyrethrin. These are best applied when the ticks are in their small nymphal stage during the month of May and early June. See the CT Tick Management Handbook written by the CT Agricultural Experiment Station for much more detailed information.

Written by Carol Quish

Originally posted by UConn Extension in 2014.

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Water Reuse in Europe – What’s Next?

city-continent-country-269790.jpg

Water is perhaps the most abundant yet inaccessible resource available on Earth. The amount of water that is currently available for use is infinitesimal compared to the quantity of unusable water in oceans and ice caps. Water scarcity has become a dire problem. An obvious solution is reusing water that is available. Unfortunately, the potential for reuse has not been fully realized in the European Union (EU). The current challenges include:

  1. Water reuse expenses are high (developing wastewater treatment plants (WTPs), potable and non-potable water segregation)
  2. Lack of unanimous legislation across EU members
  3. Scope for public distrust (capitalism-based paranoia, health risks)

The European Commission (EC) has initiated a discussion aimed at overcoming these problems and promote safe water reuse protocols. Based on a legislative proposal of minimum quality requirements (MQR) by the EC, their Joint Research Centre (JRC) was commissioned to prepare a scientific report (now published) which proposed MQR for reusing water on two primary fronts – aquifer recharge & agricultural irrigation.

The EC asked the Scientific Committee on Health, Environment and Emerging Risks (SCHEER) and the European Food Safety Authority (EFSA) for their scientific advice and commentary (Rizzo et al., 2018). SCHEER  believes the MQR proposal does not provide sufficient shielding against 3 primary environmental risks.

●     Effluent contamination risk: There would be an unwanted occurrence of Water Framework Directive (WFD) priority chemicals and the contaminants of emerging concern (CECs) such as personal hygiene and beauty products, pharmaceuticals, microplastics, etc. in WTP effluents (Pal et al., 2014).

●     Antibiotic resistance risk: A pressing issue is a possibility of WTP effluents creating antibiotic resistance in irrigated crops. These effluents have a high proportion of mobile genetic elements like bacteria that carry antibiotic resistant genes which could assist antibiotic resistance in plants and soil (Rizzo et al., 2013; Becerra-Castro et al., 2015). The report failed to account for this known risk to water resources as well as humans and animals. 

●     Microbiological risk: The report does not account for the microbiological risk involving bacterial regrowth in treated wastewater storages which supply to irrigation. Extra care is needed as bacterial regrowth cannot be completely stopped under regular operating conditions found in WTPs (Li et al., 2013; Fiorentino et al., 2015).

These risks can be minimized and water reuse can be made safer with a minimum required tertiary treatment that includes conventional filtration and then disinfection. However other processes such as adsorption and advanced oxidation should be implemented when economically sustainable.

An appropriate program for monitoring should be implemented that checks CECs, indicators of antibiotic resistance, and disinfection byproducts along with the conventional parameters (TSS, COD, etc.). The precise nature of monitoring should be based on the current advancements at the EU level.

Are you interested in learning more about advanced wastewater treatment and reuse technologies. Contact Active Water Solutions today.

 

[Read More …]

Water Reuse in Europe – What’s Next?

city-continent-country-269790.jpg

Water is perhaps the most abundant yet inaccessible resource available on Earth. The amount of water that is currently available for use is infinitesimal compared to the quantity of unusable water in oceans and ice caps. Water scarcity has become a dire problem. An obvious solution is reusing water that is available. Unfortunately, the potential for reuse has not been fully realized in the European Union (EU). The current challenges include:

  1. Water reuse expenses are high (developing wastewater treatment plants (WTPs), potable and non-potable water segregation)
  2. Lack of unanimous legislation across EU members
  3. Scope for public distrust (capitalism-based paranoia, health risks)

The European Commission (EC) has initiated a discussion aimed at overcoming these problems and promote safe water reuse protocols. Based on a legislative proposal of minimum quality requirements (MQR) by the EC, their Joint Research Centre (JRC) was commissioned to prepare a scientific report (now published) which proposed MQR for reusing water on two primary fronts – aquifer recharge & agricultural irrigation.

The EC asked the Scientific Committee on Health, Environment and Emerging Risks (SCHEER) and the European Food Safety Authority (EFSA) for their scientific advice and commentary (Rizzo et al., 2018). SCHEER  believes the MQR proposal does not provide sufficient shielding against 3 primary environmental risks.

●     Effluent contamination risk: There would be an unwanted occurrence of Water Framework Directive (WFD) priority chemicals and the contaminants of emerging concern (CECs) such as personal hygiene and beauty products, pharmaceuticals, microplastics, etc. in WTP effluents (Pal et al., 2014).

●     Antibiotic resistance risk: A pressing issue is a possibility of WTP effluents creating antibiotic resistance in irrigated crops. These effluents have a high proportion of mobile genetic elements like bacteria that carry antibiotic resistant genes which could assist antibiotic resistance in plants and soil (Rizzo et al., 2013; Becerra-Castro et al., 2015). The report failed to account for this known risk to water resources as well as humans and animals. 

●     Microbiological risk: The report does not account for the microbiological risk involving bacterial regrowth in treated wastewater storages which supply to irrigation. Extra care is needed as bacterial regrowth cannot be completely stopped under regular operating conditions found in WTPs (Li et al., 2013; Fiorentino et al., 2015).

These risks can be minimized and water reuse can be made safer with a minimum required tertiary treatment that includes conventional filtration and then disinfection. However other processes such as adsorption and advanced oxidation should be implemented when economically sustainable.

An appropriate program for monitoring should be implemented that checks CECs, indicators of antibiotic resistance, and disinfection byproducts along with the conventional parameters (TSS, COD, etc.). The precise nature of monitoring should be based on the current advancements at the EU level.

Are you interested in learning more about advanced wastewater treatment and reuse technologies. Contact Active Water Solutions today.

 

[Read More …]

The Impact of Climate Change on Water Supplies

astronomy-discovery-earth-2422.jpg

Today climate change and its associated impacts have become the center of attention for water resources’ planners and researchers all over the world. The lack of concrete understanding of the potential risks associated with these impacts and the fact that they will not be uniform across the world added to the complexity of the task. Currently, studies show that climate change will have an impact on reservoir water supplies in terms of both quality and quantity. Therefore, when designing for future water treatment processes, designers have to factor the climate change projections into their systems’ designs and operations. As a result, The Water Research Foundation in its report Assessment of the Impacts of Climate Change on Reservoir Water Quality examined how climate change alters the risks facing the reservoirs’ water quality. The aim of this research was to enhance the estimation of the future potential impacts of climate change on water reservoirs, quantitively, through designing and testing a new approach.   

According to the Intergovernmental Panel on Climate Change (IPCC), due to climate change, freshwater resources are expected to be scarce all over the world, especially in arid and semi-arid areas. Moreover, climate change poses a risk to the quality of potable water as it will accelerate the growth of algae and increase the frequency of cyanobacterial blooms in the reservoirs which will affect the safe water supply to humans. Hence, the researchers focused their efforts on trying to find ways to reduce these potential impacts and provide tools to prevent them.    

The researchers identified the increase in algal growth, turbidity, and dissolved organic carbon (DOC) loads as the most-likely impacts of the climate change on the reservoirs. Therefore, the research team used an integrated modeling scheme to study three potable water supply reservoirs. The choice of these reservoirs took into account the type of climate in which the reservoirs are located, their role in the potable water supply chain, and the availability of historical data as the research team believed that this would be the best way to measure the potential impacts of climate change and compare the resilience of the different water supply systems; these chosen reservoirs were: Hsin-Shan Reservoir in Taiwan; Occoquan Reservoir in Virginia, USA; and Myponga Reservoir in Australia. 

Regarding the Hsin-Shan Reservoir, this reservoir is located in Northern Taiwan and is the largest drinking water source in the region. The reservoir is found in a humid, sub-tropical climate, and located in a tropical cyclone area. For this reservoir, the researchers examined the negative impacts of climate change on the water quality, both, in the near term (2020–2039) and long-term (2080–2099). This reservoir is both small and deep in size which increases the vulnerability of the quality of its water to climate change, especially from thermal stratification. From the collected data, the research team deduced that there is an increase in the intensity of the tropical cyclone activity due to the rise in atmospheric water vapor and surface water temperature from a warming climate. Moreover, they concluded that an increase in atmospheric temperature was the primary reason for the lower water quality in the reservoir because it will lower the dissolved oxygen concentrations and release more phosphorus from the sediments.

On the other hand, the Occoquan Reservoir is located in Northern Virginia in which The Upper Broad Run and Middle Broad Run watersheds can be found in its northwestern part. These watersheds drain into Lake Manassas which is an artificial lake that is a vital potable water supply for the surrounding area. The climate in the reservoir’s area is classified as temperate, and the area experiences four distinct seasons. The research team projected the potential impacts using two models based on the mean yearly precipitations and the mean yearly surface air temperature. These parameters were chosen to depict the upper and lower limits of the other different models and to denote a “hot and wet” and “cool and dry” climate conditions. From these models, the researchers were able to conclude that there will be a future thermal stratification in Lake Manassas which can expand and intensify thanks to the global climate change. Furthermore, increased water flow in the streams and channels is expected due to climate change which will result in an increase in nutrients pollution in the reservoir. Nevertheless, Lake Manassas could serve as a mitigator of these negative impacts within the reservoir and increase the resiliency of the region to the adverse effects of climate change.

Finally, regarding The Myponga Reservoir, this reservoir is located in Southern Adelaide and receives water from a natural catchment. This region has a Mediterranean-like climate with hot, dry summers and mild winters and the water is treated through a conventional treatment process that comprises of flocculation and chlorination at a close by water treatment plant. The results of the experiments done on this reservoir show that the water quality of the reservoir will suffer significantly from the higher demand. Moreover, from the modeling simulations and the data collected, the research team is confident that the Myponga River will most probably stop supplying water to the Myponga Reservoir in the future because the rising temperatures may result in less precipitation. In addition, they believe that a decreased inflow from the catchment and increased evaporation will put future stress on this particular water system; and that the nutrient loading will decrease due to the drop in both concentration and volume. Nonetheless, this recent decrease might not lead to less productivity from the reservoir because the internal nutrient cycle will be able to maintain this productivity.

From all the above observations, the researchers believe that it is vital to actively manage the watersheds to stop and control the contaminant runoff. To achieve this objective, the use of an integrated-modeling approach can help inform business-related future risks related to catchment-derived nutrients, DOC, and microbial contamination. In conclusion, based on the research findings, a number of conclusions can be reached: first, where air temperatures increase, surface water temperatures will rise. Second, the increase in temperature will impact the nutrient dynamics based on stratification behavior and intensify the phytoplankton productivity. Finally, the researchers recommend that destratification approaches to be implemented in the future designs and operations of the water reservoirs, as well as, the solutions to prevent and control contaminant runoff. Ultimately, utilities will have to develop more proactive strategies to lower the amount of in-stream and nonpoint source nutrient loads.

 

[Read More …]

The Impact of Climate Change on Water Supplies

astronomy-discovery-earth-2422.jpg

Today climate change and its associated impacts have become the center of attention for water resources’ planners and researchers all over the world. The lack of concrete understanding of the potential risks associated with these impacts and the fact that they will not be uniform across the world added to the complexity of the task. Currently, studies show that climate change will have an impact on reservoir water supplies in terms of both quality and quantity. Therefore, when designing for future water treatment processes, designers have to factor the climate change projections into their systems’ designs and operations. As a result, The Water Research Foundation in its report Assessment of the Impacts of Climate Change on Reservoir Water Quality examined how climate change alters the risks facing the reservoirs’ water quality. The aim of this research was to enhance the estimation of the future potential impacts of climate change on water reservoirs, quantitively, through designing and testing a new approach.   

According to the Intergovernmental Panel on Climate Change (IPCC), due to climate change, freshwater resources are expected to be scarce all over the world, especially in arid and semi-arid areas. Moreover, climate change poses a risk to the quality of potable water as it will accelerate the growth of algae and increase the frequency of cyanobacterial blooms in the reservoirs which will affect the safe water supply to humans. Hence, the researchers focused their efforts on trying to find ways to reduce these potential impacts and provide tools to prevent them.    

The researchers identified the increase in algal growth, turbidity, and dissolved organic carbon (DOC) loads as the most-likely impacts of the climate change on the reservoirs. Therefore, the research team used an integrated modeling scheme to study three potable water supply reservoirs. The choice of these reservoirs took into account the type of climate in which the reservoirs are located, their role in the potable water supply chain, and the availability of historical data as the research team believed that this would be the best way to measure the potential impacts of climate change and compare the resilience of the different water supply systems; these chosen reservoirs were: Hsin-Shan Reservoir in Taiwan; Occoquan Reservoir in Virginia, USA; and Myponga Reservoir in Australia. 

Regarding the Hsin-Shan Reservoir, this reservoir is located in Northern Taiwan and is the largest drinking water source in the region. The reservoir is found in a humid, sub-tropical climate, and located in a tropical cyclone area. For this reservoir, the researchers examined the negative impacts of climate change on the water quality, both, in the near term (2020–2039) and long-term (2080–2099). This reservoir is both small and deep in size which increases the vulnerability of the quality of its water to climate change, especially from thermal stratification. From the collected data, the research team deduced that there is an increase in the intensity of the tropical cyclone activity due to the rise in atmospheric water vapor and surface water temperature from a warming climate. Moreover, they concluded that an increase in atmospheric temperature was the primary reason for the lower water quality in the reservoir because it will lower the dissolved oxygen concentrations and release more phosphorus from the sediments.

On the other hand, the Occoquan Reservoir is located in Northern Virginia in which The Upper Broad Run and Middle Broad Run watersheds can be found in its northwestern part. These watersheds drain into Lake Manassas which is an artificial lake that is a vital potable water supply for the surrounding area. The climate in the reservoir’s area is classified as temperate, and the area experiences four distinct seasons. The research team projected the potential impacts using two models based on the mean yearly precipitations and the mean yearly surface air temperature. These parameters were chosen to depict the upper and lower limits of the other different models and to denote a “hot and wet” and “cool and dry” climate conditions. From these models, the researchers were able to conclude that there will be a future thermal stratification in Lake Manassas which can expand and intensify thanks to the global climate change. Furthermore, increased water flow in the streams and channels is expected due to climate change which will result in an increase in nutrients pollution in the reservoir. Nevertheless, Lake Manassas could serve as a mitigator of these negative impacts within the reservoir and increase the resiliency of the region to the adverse effects of climate change.

Finally, regarding The Myponga Reservoir, this reservoir is located in Southern Adelaide and receives water from a natural catchment. This region has a Mediterranean-like climate with hot, dry summers and mild winters and the water is treated through a conventional treatment process that comprises of flocculation and chlorination at a close by water treatment plant. The results of the experiments done on this reservoir show that the water quality of the reservoir will suffer significantly from the higher demand. Moreover, from the modeling simulations and the data collected, the research team is confident that the Myponga River will most probably stop supplying water to the Myponga Reservoir in the future because the rising temperatures may result in less precipitation. In addition, they believe that a decreased inflow from the catchment and increased evaporation will put future stress on this particular water system; and that the nutrient loading will decrease due to the drop in both concentration and volume. Nonetheless, this recent decrease might not lead to less productivity from the reservoir because the internal nutrient cycle will be able to maintain this productivity.

From all the above observations, the researchers believe that it is vital to actively manage the watersheds to stop and control the contaminant runoff. To achieve this objective, the use of an integrated-modeling approach can help inform business-related future risks related to catchment-derived nutrients, DOC, and microbial contamination. In conclusion, based on the research findings, a number of conclusions can be reached: first, where air temperatures increase, surface water temperatures will rise. Second, the increase in temperature will impact the nutrient dynamics based on stratification behavior and intensify the phytoplankton productivity. Finally, the researchers recommend that destratification approaches to be implemented in the future designs and operations of the water reservoirs, as well as, the solutions to prevent and control contaminant runoff. Ultimately, utilities will have to develop more proactive strategies to lower the amount of in-stream and nonpoint source nutrient loads.

 

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