Bacteria and Beaches
Avoiding the mix
Many parents cringe at the sight, knowing how disappointed their children will be. Swimmers, canoers, and surfers express aggravation and frustration. Nearby businesses contemplate their monetary losses. What causes this discomfort? Signs that have become all too frequent a sight: “Beach Closed.”
According to “Testing the Waters—2006,” an annual report published by the Natural Resources Defense Council (NRDC), more than 20,000 days of beach closings and advisories were issued in the United States in 2005. This constituted a 5% increase over 2004 and was the largest number in the 16 years that the NRDC has been counting. The report covers 29 coastal and Great Lakes states and four territories. Much of the data were gathered from EPA monitoring stations. Results showed that 8% of the samples taken were not in compliance with the EPA’s Beach Environmental Assessment and Coastal Health Act, which sets the current standards. Some of the closings doubtless resulted from better monitoring and testing.
The EPA missed an October 2005 deadline to have new regulations in place for beach safety to replace outdated standards from 1986. The NRDC has filed suit to force the EPA to accelerate the issuance of the new standards and reinforce the safety of the public. Many local governments are not waiting for EPA guidance but are instituting tighter safety guidelines now.
Beach advisories and closings generally are based on measurement of bacteria levels. Two types of bacteria are used as indicator bacteria: E. coli and Enterococcus. These bacteria, found in warm-blooded animals, are not usually a danger to people, but they are fairly hardy, and if they are present in samples, more potent pathogens also may be present. If they are not found, it is less likely that other pathogens are present. Their presence indicates the possibility of pathogens that could sicken people. The current standards are a daily maximum of 104 Enterococci colony-forming units per 100 milliliters of marine water and 220 E. coli colony-forming units per 100 milliliters of fresh water. The scope of the problem can be seen in the fact that 200 US beaches exceeded these standards at least 25% of the time in 2005.
Closed beaches not only affect the public but also have a severe impact on the economies of beachfront towns and businesses. A 2005 study by the National Oceanographic Partnership Program estimated that improving beach safety could increase revenues by $94 million in California and $55 million in Florida. Stormwater and water-quality managers of these beachfront municipalities are working hard to increase beach safety.
They comprehend the problems they face in controlling bacterial invasion of beaches. But pinpointing the exact source of contamination, detecting and monitoring bacterial levels in a realistic amount of time, and containing a pollutant when a spill occurs are challenges for all.
Managers need to know the sources of bacteria reaching the beaches so they can set up methods to stop the contamination. According to the report, 63% of the total were from unknown sources. That percentage is a decrease from 2004. The unknown sources may be sewer overflows, leaking septic systems, agricultural or livestock operations, wildlife or pet populations, or pollution from point sources, and the technology is not always in place to determine the exact source. Source DNA tracking is still fairly expensive and therefore not always feasible. Polluted stormwater runoff contributed to 23% of the total in 2005, an increase of 1,189 days over 2004. Sewage spills, including combined sewer overflows, sanitary sewer overflows, breaks or blockages in sewer lines, and faulty septic systems, caused about 4% of the closings and advisories.
As is true with other stormwater runoff pollutants, bacteria contamination is highest in first-flush conditions. However, dry-weather runoff also can contain high levels of contaminants.
Prevention
The first step in any clean-water program must be prevention. The public needs to be educated about the causes of contamination of beaches and other waterways. In a study conducted by Weston Solutions of Carlsbad, CA, irrigation was found to be the largest contributing factor to the contamination of some California beaches. The Prima Deschecha watershed drains to a scour pond on Poche Beach, in San Clemente, CA. High levels of E. coli had closed the beach more often than any other beach in Orange County. The beach was listed as an impaired water body. California Assembly Bill 411 (AB411) sets levels at which a beach must be closed, and Poche Beach regularly surpassed those levels. Orange County contracted with Weston Solutions to perform a yearlong study of the channel and beach, costing $200,000.
The drainage from the watershed passes through a concrete-lined flood control channel, the M01. About 95% of the channel is completely covered, preventing any sunlight interaction. The M01, about 5 miles long, drains 4,400 acres of primarily residential land. About 20% of the land is the Shorecliffs Golf Course. A large landfill operates at the start of the watershed. The largest additional drainage into the M01 is the Cascadita Channel, a soft-bottom channel that is open to sunlight.
During the yearlong study conducted by Weston Solutions, samples were collected and quantitative polymerase chain reaction (Q/PCR) analysis was accomplished. Q/PCR analyses provide a count of the bacteria present, as well as species-specific identification. By this process, it can be determined if the bacteria came from human, animal, or bird sources.
During dry weather, the M01 has a flow rate of 0.62 million gallons a day. The scour pond at the end of the channel is mostly fresh water, but sea water does wash into the western end.
The final results of the Poche Beach study showed that the main source of bacterial contamination came from irrigation runoff. When sprinklers run on already-damp soil, the runoff intensifies and carries with it bacteria from dog feces and fertilizers. With smart timers that turn on sprinklers only when the moisture content of soil is low, and with a strong education program for homeowners, this problem can be reduced.
The study also found that more than 75% of the bacterial load comes from the top portion of the watershed and is not of human origin. The Cascadita Channel adds only 1% to the load.
In other areas, prevention may entail spending funds for cleanup of organic material and bird feces from beaches. A study presented at StormCon in 2006, written by Daniel McCoy and Larissa Aumand of Weston Solutions, highlighted the challenges. Pacific Beach Point in La Jolla, CA, is a small isolated beach that frequently had high indicator bacteria levels. This study was intended to determine whether kelp piles on the beach were providing incubation for the bacteria and whether brine flies also contributed to the spread.
The conclusions were that kelp does facilitate growth to a great degree, a logarithmic amount over the span of just one day. The study also found that brine flies have the potential to spread bacteria to the kelp, increasing the levels of indicator bacteria on the beach. Whether bacteria reached the kelp piles from contaminated stormwater or through deposition by the flies, the bacteria grew almost as well as that cultured in a lab. The contamination spread over the beach, causing high enough levels for it to be closed.
For a situation similar to the one at Pacific Beach Point, a prevention method could be as simple as removing kelp piles from the beach.
When prevention is not enough, or when a sewage spill occurs, the increasing bacteria levels must be detected.
Detection
Miguel Molina, product manager for Hach Environmental of Loveland, CO, agrees that sampling and detection of bacteria are thorny problems. For an automatic sampler to be accurate, everything must be sterile, the sample must be kept cool enough so that bacteria present don’t degrade, and people must be available to pick up the samples and run the analyses in the lab.
Hach Environmental has a series of samplers that are refrigerated to 4°C to preserve bacterial counts. When integrated with a flowmeter to trigger sampling, the setup sounds a remote alarm to notify workers when samples need to be picked up. When instruments to measure pH levels, turbidity, nutrient levels, dissolved oxygen, and conductivity are added, the entire package provides a comprehensive look at the health of a stream or another water body. “Bacteria is the biggest challenge,” Molina adds.
Maintenance for automatic samplers checking bacteria levels involves replacing the tubing in the pump. The frequency of replacement depends on use. “The biggest problem with the samplers is vandalism,” Molina notes.
New faster methods of detecting levels of indicator bacteria may be available in a few years. Larissa Aumand of Weston Solutions says that she is aware of companies working on rapid tests. Studies are under way to correlate the rapid test results with historic data to obtain databases of information.
One of the problems with monitoring is the number of personnel required to collect and analyze samples of every beach. One state, Massachusetts, has a plan to prioritize its monitoring schedule. The Massachusetts Department of Public Health (MDPH) sampled and tested more than 500 beaches for four years and added the results to a database. It then developed the Public Health-Based Beach Evaluation, Classification, and Tiered Monitoring Plan to prioritize sampling and cleanup efforts. Heavily used beaches that have consistently shown high levels of indicator bacteria are classified as Tier 1, and samples are taken more than once a week. Tier 2 beaches are tested once a week, and Tier 3 beaches every two to three weeks. A beach can be reclassified to another tier if conditions change.
In 2005, Revere Beach in Revere and Lake Quinsigamond in Worcester, MA, had to be closed due to sewage spills, and other beaches were impacted by algae bloom. An MDPH Web site alerts the public to closed beaches. Beach conditions were shown to be improving during the 2005 season.
Identification
Many times, identifying the specific source of contamination must be accomplished before mitigation can occur. With new techniques of DNA source tracking, identification is more feasible. According to Thierry Tamers of Source Molecular Corp. in Miami, FL, “The field is moving toward quantitative analysis.” Stormwater managers want to send in a sample and be told what it is and where it came from.
With grants from the EPA and funds from local communities, a study was conducted of the Rouge River in southeastern Michigan. The Rouge River watershed contains 48 communities and drains 466 square miles. Water flowing through the watershed goes into the Detroit River and eventually into Lake Erie. The land use is a mix of urban and suburban areas. The system of 127 river miles and 400 lakes and ponds is on the state’s 303(d) list of impaired water bodies.
E. coli monitoring from May to October 2005 revealed 93% of the samples exceeded state standards. Before water quality could be improved, the sources of the contamination needed to be found. A bacterial source tracking (BST) program was initiated.
Samples were taken at each location during dry and wet weather. Analyses for E. coli and BST tests for human bacteroidetes and human Enterococcus were performed. The BST samples were packed in ice and shipped to Source Molecular for evaluation. The results showed that human sources of bacteria were found in all sample locations during wet weather. With this knowledge, communities can decide where resources should be spent to minimize the human component. The confirmation of prevalence of bacteria from human sources leads to the conclusion that more inspection of septic systems and searching for illicit sewer connections is necessary. Improvements to infrastructure to prevent combined sewer overflows and upgrades in stormwater runoff treatment can make a big difference. This information was added to the Rouge Project database and in a TMDL report to be released by the Michigan Department of Environmental Quality sometime this year.
One of the most peaceful beaches in Florida is also one of the most bacteria laden. Shired Island is surrounded by a wildlife refuge, yet samples from the beach consistently read high for indicator bacteria. Officials speculate that the levels come from septic tanks. The nearest town, Horseshoe Beach, depends exclusively on septic tanks and residents acknowledge the problem. Studies indicate that during winter months, human waste is the biggest contributor of bacteria. The town wishes to build a wastewater system, but the high cost has prevented it so far. It is hoping to receive state and federal grants to build the system.
Mitigation
Once bacterial contamination has been detected, the process of mitigation begins. Depending on the source, different systems can be installed to reduce the number of beach closing days.
Already mentioned in this article are fixes such as removing bird or dog feces and kelp piles. Other than surface removal, stormwater runoff may need treatment. A product by AbTech Industries of Scottsdale, AZ, is designed to remove microbes from stormwater.
The Smart Sponge is a filter manufactured from polymers and removes both oil and bacteria. A proprietary ingredient bound to the polymer chains kills a variety of microbes, including E. coli, Enterococcus, Salmonella, and others.
The Rhode Island Department of Transportation received funding to investigate ways of improving highway stormwater runoff that was impacting Scarborough Beach. The Smart Sponge technology was installed in catch basin inserts, and influent and effluent testing was performed. Twenty dry-weather tests were conducted, along with testing during three storm events. Tests showed a reduction of 82% to 90% during dry-weather conditions and 69% to 89% during wet weather.
The City of Long Beach, CA, also is using Smart Sponge technology to help clean up beaches. Over a three-year period, the city spent approximately $850,000 to install 1,950 Smart Sponge filters in catch basin inlets. Tom Leary, Stormwater Management Division officer, says, “Our number-one priority is to protect the public’s health. With over 11 miles of public beaches and Colorado Lagoon, one of the few remaining inland recreational water bodies, the presence of bacteria and other harmful pathogens in our stormwater and urban runoff poses risks to human health, particularly after heavy rainfall.” So far, the city has seen an average bacterial destruction rate of 79% up to a maximum amount of 97%.
The Smart Sponge also takes care of hydrocarbons and sediment. Leary reports that installation and maintenance has been surprisingly easy. The lightweight system is installed without requiring a crane. So far, units have lasted as long as three years before replacement.
With the help of Senator Joe Lieberman, Norwalk, CT, has instigated installation of Smart Sponge technology to improve the water quality of Long Island Sound. Money for the Filter Project comes from an EPA grant, the City of Norwalk, and Soundkeeper Inc., an organization charged with the protection of Long Island Sound. Costs of the program were $500,000.
Ultra-Urban Filters with Smart Sponge Plus were installed in 275 catch basins around Norwalk in early 2006. Initial tests show an average bacteria removal rate of over 75% and a maximum of 99.9%. Terry Backer, the soundkeeper and the executive director of Soundkeeper Inc., says, “The Filter Project will help clean our waters for swimming, boating, and shellfishing and improve the general public health. We are very excited about the early success of the Filter Project and the rate at which the system has been implemented.”
A new plant at Dana Point, CA, has a different treatment protocol—treating stormwater with ozone. The plant was constructed with local, state, and federal funds and cost more than $7 million. In past years, the Salt Creek Beach was closed as much as 70% of the time. Runoff from the storm drains passes through the plant, where it is exposed to ozone, which kills bacteria.
In March 2007, the City of Dana Point was able to report that beach water quality had improved to the point that the Salt Creek beaches were being delisted from the state’s 303(d) list.
Future Advances
Gretel Roberts grew up in New Zealand and received her doctorate in microbiology. She came to the United States about five years ago and has continued work on clean beaches with Weston Solutions. Her work on risk assessment of beach closings has led to studies about the connection between risk of illness at beaches and water-quality indicators. In some research, a disconnect between the two conditions is seen. At StormCon in 2007, she will present a paper about a risk assessment model that was developed by the World Health Organization and the EPA. The model has not yet been implemented in the United States, but New Zealand has been using it for the last five years.
Advertisement
Roberts says, “The increase in population along our beaches requires us to be more vigilant about the safety of bathing waters.” Her colleague, Daniel McCoy, agrees: “We must address this issue to enhance our beaches.”
Improving the safety of our beaches enhances the economics, recreational opportunities, and enjoyment of millions of our citizens. Cleaner beaches is a worthy goal for any coastal stormwater manager.
Author's Bio: Frequent contributor Roberta Baxter specializes in science and technology topics.
September 2007
Bacteria and Beaches
Avoiding the mix
Many parents cringe at the sight, knowing how disappointed their children will be. Swimmers, canoers, and surfers express aggravation and frustration. Nearby businesses contemplate their monetary losses. What causes this discomfort? Signs that have become all too frequent a sight: “Beach Closed.”
According to “Testing the Waters—2006,” an annual report published by the Natural Resources Defense Council (NRDC), more than 20,000 days of beach closings and advisories were issued in the United States in 2005. This constituted a 5% increase over 2004 and was the largest number in the 16 years that the NRDC has been counting. The report covers 29 coastal and Great Lakes states and four territories. Much of the data were gathered from EPA monitoring stations. Results showed that 8% of the samples taken were not in compliance with the EPA’s Beach Environmental Assessment and Coastal Health Act, which sets the current standards. Some of the closings doubtless resulted from better monitoring and testing.
The EPA missed an October 2005 deadline to have new regulations in place for beach safety to replace outdated standards from 1986. The NRDC has filed suit to force the EPA to accelerate the issuance of the new standards and reinforce the safety of the public. Many local governments are not waiting for EPA guidance but are instituting tighter safety guidelines now.
Beach advisories and closings generally are based on measurement of bacteria levels. Two types of bacteria are used as indicator bacteria: E. coli and Enterococcus. These bacteria, found in warm-blooded animals, are not usually a danger to people, but they are fairly hardy, and if they are present in samples, more potent pathogens also may be present. If they are not found, it is less likely that other pathogens are present. Their presence indicates the possibility of pathogens that could sicken people. The current standards are a daily maximum of 104 Enterococci colony-forming units per 100 milliliters of marine water and 220 E. coli colony-forming units per 100 milliliters of fresh water. The scope of the problem can be seen in the fact that 200 US beaches exceeded these standards at least 25% of the time in 2005.
Closed beaches not only affect the public but also have a severe impact on the economies of beachfront towns and businesses. A 2005 study by the National Oceanographic Partnership Program estimated that improving beach safety could increase revenues by $94 million in California and $55 million in Florida. Stormwater and water-quality managers of these beachfront municipalities are working hard to increase beach safety.
They comprehend the problems they face in controlling bacterial invasion of beaches. But pinpointing the exact source of contamination, detecting and monitoring bacterial levels in a realistic amount of time, and containing a pollutant when a spill occurs are challenges for all.
Managers need to know the sources of bacteria reaching the beaches so they can set up methods to stop the contamination. According to the report, 63% of the total were from unknown sources. That percentage is a decrease from 2004. The unknown sources may be sewer overflows, leaking septic systems, agricultural or livestock operations, wildlife or pet populations, or pollution from point sources, and the technology is not always in place to determine the exact source. Source DNA tracking is still fairly expensive and therefore not always feasible. Polluted stormwater runoff contributed to 23% of the total in 2005, an increase of 1,189 days over 2004. Sewage spills, including combined sewer overflows, sanitary sewer overflows, breaks or blockages in sewer lines, and faulty septic systems, caused about 4% of the closings and advisories.
As is true with other stormwater runoff pollutants, bacteria contamination is highest in first-flush conditions. However, dry-weather runoff also can contain high levels of contaminants.
Prevention
The first step in any clean-water program must be prevention. The public needs to be educated about the causes of contamination of beaches and other waterways. In a study conducted by Weston Solutions of Carlsbad, CA, irrigation was found to be the largest contributing factor to the contamination of some California beaches. The Prima Deschecha watershed drains to a scour pond on Poche Beach, in San Clemente, CA. High levels of E. coli had closed the beach more often than any other beach in Orange County. The beach was listed as an impaired water body. California Assembly Bill 411 (AB411) sets levels at which a beach must be closed, and Poche Beach regularly surpassed those levels. Orange County contracted with Weston Solutions to perform a yearlong study of the channel and beach, costing $200,000.
The drainage from the watershed passes through a concrete-lined flood control channel, the M01. About 95% of the channel is completely covered, preventing any sunlight interaction. The M01, about 5 miles long, drains 4,400 acres of primarily residential land. About 20% of the land is the Shorecliffs Golf Course. A large landfill operates at the start of the watershed. The largest additional drainage into the M01 is the Cascadita Channel, a soft-bottom channel that is open to sunlight.
During the yearlong study conducted by Weston Solutions, samples were collected and quantitative polymerase chain reaction (Q/PCR) analysis was accomplished. Q/PCR analyses provide a count of the bacteria present, as well as species-specific identification. By this process, it can be determined if the bacteria came from human, animal, or bird sources.
During dry weather, the M01 has a flow rate of 0.62 million gallons a day. The scour pond at the end of the channel is mostly fresh water, but sea water does wash into the western end.
The final results of the Poche Beach study showed that the main source of bacterial contamination came from irrigation runoff. When sprinklers run on already-damp soil, the runoff intensifies and carries with it bacteria from dog feces and fertilizers. With smart timers that turn on sprinklers only when the moisture content of soil is low, and with a strong education program for homeowners, this problem can be reduced.
The study also found that more than 75% of the bacterial load comes from the top portion of the watershed and is not of human origin. The Cascadita Channel adds only 1% to the load.
In other areas, prevention may entail spending funds for cleanup of organic material and bird feces from beaches. A study presented at StormCon in 2006, written by Daniel McCoy and Larissa Aumand of Weston Solutions, highlighted the challenges. Pacific Beach Point in La Jolla, CA, is a small isolated beach that frequently had high indicator bacteria levels. This study was intended to determine whether kelp piles on the beach were providing incubation for the bacteria and whether brine flies also contributed to the spread.
The conclusions were that kelp does facilitate growth to a great degree, a logarithmic amount over the span of just one day. The study also found that brine flies have the potential to spread bacteria to the kelp, increasing the levels of indicator bacteria on the beach. Whether bacteria reached the kelp piles from contaminated stormwater or through deposition by the flies, the bacteria grew almost as well as that cultured in a lab. The contamination spread over the beach, causing high enough levels for it to be closed.
For a situation similar to the one at Pacific Beach Point, a prevention method could be as simple as removing kelp piles from the beach.
When prevention is not enough, or when a sewage spill occurs, the increasing bacteria levels must be detected.
Detection
Miguel Molina, product manager for Hach Environmental of Loveland, CO, agrees that sampling and detection of bacteria are thorny problems. For an automatic sampler to be accurate, everything must be sterile, the sample must be kept cool enough so that bacteria present don’t degrade, and people must be available to pick up the samples and run the analyses in the lab.
Hach Environmental has a series of samplers that are refrigerated to 4°C to preserve bacterial counts. When integrated with a flowmeter to trigger sampling, the setup sounds a remote alarm to notify workers when samples need to be picked up. When instruments to measure pH levels, turbidity, nutrient levels, dissolved oxygen, and conductivity are added, the entire package provides a comprehensive look at the health of a stream or another water body. “Bacteria is the biggest challenge,” Molina adds.
Maintenance for automatic samplers checking bacteria levels involves replacing the tubing in the pump. The frequency of replacement depends on use. “The biggest problem with the samplers is vandalism,” Molina notes.
New faster methods of detecting levels of indicator bacteria may be available in a few years. Larissa Aumand of Weston Solutions says that she is aware of companies working on rapid tests. Studies are under way to correlate the rapid test results with historic data to obtain databases of information.
One of the problems with monitoring is the number of personnel required to collect and analyze samples of every beach. One state, Massachusetts, has a plan to prioritize its monitoring schedule. The Massachusetts Department of Public Health (MDPH) sampled and tested more than 500 beaches for four years and added the results to a database. It then developed the Public Health-Based Beach Evaluation, Classification, and Tiered Monitoring Plan to prioritize sampling and cleanup efforts. Heavily used beaches that have consistently shown high levels of indicator bacteria are classified as Tier 1, and samples are taken more than once a week. Tier 2 beaches are tested once a week, and Tier 3 beaches every two to three weeks. A beach can be reclassified to another tier if conditions change.
In 2005, Revere Beach in Revere and Lake Quinsigamond in Worcester, MA, had to be closed due to sewage spills, and other beaches were impacted by algae bloom. An MDPH Web site alerts the public to closed beaches. Beach conditions were shown to be improving during the 2005 season.
Identification
Many times, identifying the specific source of contamination must be accomplished before mitigation can occur. With new techniques of DNA source tracking, identification is more feasible. According to Thierry Tamers of Source Molecular Corp. in Miami, FL, “The field is moving toward quantitative analysis.” Stormwater managers want to send in a sample and be told what it is and where it came from.
With grants from the EPA and funds from local communities, a study was conducted of the Rouge River in southeastern Michigan. The Rouge River watershed contains 48 communities and drains 466 square miles. Water flowing through the watershed goes into the Detroit River and eventually into Lake Erie. The land use is a mix of urban and suburban areas. The system of 127 river miles and 400 lakes and ponds is on the state’s 303(d) list of impaired water bodies.
E. coli monitoring from May to October 2005 revealed 93% of the samples exceeded state standards. Before water quality could be improved, the sources of the contamination needed to be found. A bacterial source tracking (BST) program was initiated.
Samples were taken at each location during dry and wet weather. Analyses for E. coli and BST tests for human bacteroidetes and human Enterococcus were performed. The BST samples were packed in ice and shipped to Source Molecular for evaluation. The results showed that human sources of bacteria were found in all sample locations during wet weather. With this knowledge, communities can decide where resources should be spent to minimize the human component. The confirmation of prevalence of bacteria from human sources leads to the conclusion that more inspection of septic systems and searching for illicit sewer connections is necessary. Improvements to infrastructure to prevent combined sewer overflows and upgrades in stormwater runoff treatment can make a big difference. This information was added to the Rouge Project database and in a TMDL report to be released by the Michigan Department of Environmental Quality sometime this year.
One of the most peaceful beaches in Florida is also one of the most bacteria laden. Shired Island is surrounded by a wildlife refuge, yet samples from the beach consistently read high for indicator bacteria. Officials speculate that the levels come from septic tanks. The nearest town, Horseshoe Beach, depends exclusively on septic tanks and residents acknowledge the problem. Studies indicate that during winter months, human waste is the biggest contributor of bacteria. The town wishes to build a wastewater system, but the high cost has prevented it so far. It is hoping to receive state and federal grants to build the system.
Mitigation
Once bacterial contamination has been detected, the process of mitigation begins. Depending on the source, different systems can be installed to reduce the number of beach closing days.
Already mentioned in this article are fixes such as removing bird or dog feces and kelp piles. Other than surface removal, stormwater runoff may need treatment. A product by AbTech Industries of Scottsdale, AZ, is designed to remove microbes from stormwater.
The Smart Sponge is a filter manufactured from polymers and removes both oil and bacteria. A proprietary ingredient bound to the polymer chains kills a variety of microbes, including E. coli, Enterococcus, Salmonella, and others.
The Rhode Island Department of Transportation received funding to investigate ways of improving highway stormwater runoff that was impacting Scarborough Beach. The Smart Sponge technology was installed in catch basin inserts, and influent and effluent testing was performed. Twenty dry-weather tests were conducted, along with testing during three storm events. Tests showed a reduction of 82% to 90% during dry-weather conditions and 69% to 89% during wet weather.
The City of Long Beach, CA, also is using Smart Sponge technology to help clean up beaches. Over a three-year period, the city spent approximately $850,000 to install 1,950 Smart Sponge filters in catch basin inlets. Tom Leary, Stormwater Management Division officer, says, “Our number-one priority is to protect the public’s health. With over 11 miles of public beaches and Colorado Lagoon, one of the few remaining inland recreational water bodies, the presence of bacteria and other harmful pathogens in our stormwater and urban runoff poses risks to human health, particularly after heavy rainfall.” So far, the city has seen an average bacterial destruction rate of 79% up to a maximum amount of 97%.
The Smart Sponge also takes care of hydrocarbons and sediment. Leary reports that installation and maintenance has been surprisingly easy. The lightweight system is installed without requiring a crane. So far, units have lasted as long as three years before replacement.
With the help of Senator Joe Lieberman, Norwalk, CT, has instigated installation of Smart Sponge technology to improve the water quality of Long Island Sound. Money for the Filter Project comes from an EPA grant, the City of Norwalk, and Soundkeeper Inc., an organization charged with the protection of Long Island Sound. Costs of the program were $500,000.
Ultra-Urban Filters with Smart Sponge Plus were installed in 275 catch basins around Norwalk in early 2006. Initial tests show an average bacteria removal rate of over 75% and a maximum of 99.9%. Terry Backer, the soundkeeper and the executive director of Soundkeeper Inc., says, “The Filter Project will help clean our waters for swimming, boating, and shellfishing and improve the general public health. We are very excited about the early success of the Filter Project and the rate at which the system has been implemented.”
A new plant at Dana Point, CA, has a different treatment protocol—treating stormwater with ozone. The plant was constructed with local, state, and federal funds and cost more than $7 million. In past years, the Salt Creek Beach was closed as much as 70% of the time. Runoff from the storm drains passes through the plant, where it is exposed to ozone, which kills bacteria.
In March 2007, the City of Dana Point was able to report that beach water quality had improved to the point that the Salt Creek beaches were being delisted from the state’s 303(d) list.
Future Advances
Gretel Roberts grew up in New Zealand and received her doctorate in microbiology. She came to the United States about five years ago and has continued work on clean beaches with Weston Solutions. Her work on risk assessment of beach closings has led to studies about the connection between risk of illness at beaches and water-quality indicators. In some research, a disconnect between the two conditions is seen. At StormCon in 2007, she will present a paper about a risk assessment model that was developed by the World Health Organization and the EPA. The model has not yet been implemented in the United States, but New Zealand has been using it for the last five years.
Roberts says, “The increase in population along our beaches requires us to be more vigilant about the safety of bathing waters.” Her colleague, Daniel McCoy, agrees: “We must address this issue to enhance our beaches.”
Improving the safety of our beaches enhances the economics, recreational opportunities, and enjoyment of millions of our citizens. Cleaner beaches is a worthy goal for any coastal stormwater manager.