Frequently Asked Questions

1. Q: Why is water contaminated with Arsenic?
  A:

Arsenic is a naturally occurring metal found in rocks and soil, which can be released into the environment through geological events such as volcanic activity and erosion. Other releases of arsenic into the environment occur through industrial processes such as production of paints, metals, soaps, dyes, drugs, semi-conductors and wood preservatives, as well as in mining and smelting.

Here in the United States most cases of arsenic contaminated water are a result of geochemical soil leaching, where naturally occurring arsenic in the rock and soil is solublized by contact with ground or surface water. While the Environmental Protection Agency (EPA) regulates the amount of arsenic an industrial process can release into the environment, oversights can occur, creating an added source of contamination.

Arsenic occurs in two common valence states, arsenite (arsenic III) and arsenate (arsenic V). Arsenic V is the easier of the two forms to remove from drinking water and most often is found in chlorinated water systems. Arsenic III is more difficult to remove and more hazardous to human health.

2. Q: Where is arsenic contaminated water found?
  A:

In the United States, high concentrations of arsenic most often are found at the foothills of mountain ranges. Western states and parts of the Midwest and New England show increasing arsenic levels well above the current EPA standard of 50 parts per billion (ppb).

3. Q: How does arsenic contaminated drinking water affect the body?
  A:

High concentrations of arsenic ingested into the body can produce lethal effects. Arsenic has long been known as a poison and has been the tool of many vengeful conspirators including, it appears, even for our earliest settlers at Jamestown, Virginia, where Spain tried to ensure the failure of the original English colony through repeated use of arsenic via an internal spy (“Secrets of the Dead II - Death at Jamestown”, PBS).

Initial effects of arsenicosis, the disease caused from excessive exposure to arsenic, include stomach pain, vomiting, skin lesions, pigmentation, difficulty in swallowing, excessive thirst, low blood pressure, convulsions and gastrointestinal problems. Long-term effects include cancer of the bladder, skin, kidney, liver, prostate, lung and nasal passages.

It currently is estimated that one in 100 people exposed to arsenic levels above 50 ppb (the current United States standard) will die from cancer.In areas where the arsenic levels are even higher, such as India and Bangladesh, one in 10 people exposed to arsenic levels above 500 ppb will suffer the same fate.

Non-cancer health effects include gangrene, limb loss, keratosis, neurological effects, cardiovascular disease, pulmonary disease, immunological and endocrine disorders, hematological disorders and reproductive/developmental problems.The EPA’s Office of Research and Development also may have discovered a link to DNA damage caused by arsenic compounds. The research shows arsenic inducing a reaction between itself and DNA causing certain genetic alterations in the DNA resulting in breakage.

In addition, arsenic is an accumulative enabler, meaning that people who are pre-disposed to various cancers, diabetes, high blood pressure and other ailments, are more likely to fall ill. Studies also have shown that arsenic may pass through the placenta, causing birth defects, and that exposure to it may negatively affect children’s intelligence levels and ability to learn.

4. Q: What is the current maximum containment level (MCL) for arsenic?
  A:

The EPA set the current MCL of arsenic in drinking water at 50 ppb in 1975, based on the Public Health Service standard originally established in 1942.A report by the National Academy of Sciences in March 1999 concluded that the standard of 50 ppb does not achieve the EPA’s goal of protecting public health and should be lowered as soon as possible.

It has been determined that 0 ppb is the only level of arsenic in water that is completely safe for human consumption.However, the cost required to implement a compliance standard of 0 ppb is too high. Prior to the end of President Clinton’s last term in office in January 2001, the EPA issued a new standard of 10 ppb for arsenic in public drinking water supplies.

In March 2001 the EPA announced that it would withdraw the 10 ppb standard until further studies related to costs associated with lowering the standard and impact on public health could be conducted. Although the EPA agrees the current standard of 50 ppb should be lowered, the agency is undecided of where the standard should lie and has requested time to gather data in order to make an appropriate decision.

Currently, the World Health Organization (WHO) and European Union (EU) set the world standard of arsenic in drinking water at 10 ppb, well below the current MCL of the United States.

5. Q: How will a revised MCL impact homeowners and industry?
  A:

The EPA estimates that approximately 13 million people in the United States routinely drink water with more than 10 parts per billion of arsenic.The proposed MCL would require that all drinking water and industry wastewater be treated to this limit by the year 2006, which has been estimated to cost consumers somewhere between $5-20/month in areas affected.Small water systems -- those serving less than 1,000 people -- will feel a greater financial impact from the new arsenic rule. The EPA estimates approximately 2,526 of 2,912 or 86 percent of small community water (groundwater) systems serving less than 3,300 people will be impacted at a 10 ppb MCL.

Recent studies indicate that treatment costs can be minimized for the small communities by implementing a point-of-use (POU) approach rather than through a centralized treatment system.A POU system is a filtration device that is attached under a household’s sink to treat the water that comes from that particular faucet. The short turn-around time for installing a POU system is one key advantage of this approach given that the majority of homeowners, parents in particular, are not willing to wait until the 2006 deadline imposed by EPA.

Since 1996, the EPA’s Drinking Water State Revolving Fund (DWSRF) has made $3.6 billion available to assist water systems in financial need with projects to improve their infrastructure. The EPA has funded more than 1000 loans for water systems in the United States.There are also federal funds available through such groups as the Housing and Urban Development’s Community Development Block Grant Program and the UNITED STATES Department of Agriculture.In 2000, the DWSRF and Rural Utilities Service together provided $1.7 billion to states and public water systems for improvements and infrastructure needs.

6. Q: What are the treatment options for removing Arsenic?
  A:

POU/POE Treatment options

Adsorption:
Advantages
1. No wasted water
2. Removal of both As (III) and (V)
3. Removal of other heavy metals such as flouride, copper, etc.
4. Safe handling and disposal.
5. Spent media meets EPA TCLP
6. Low cost option
7. No chemicals or regeneration required
Challenges
1. Requires certain contact time for optimal effectiveness
2. Competing ions in water can reduce capacity
3. Performance decreases with higher pH

Reverse Osmosis:
Advantages
1. Effectively reduces arsenic (V)
2. Provides high quality drinking water, removing other dissolved contaminants
3. Improves taste/odor, aesthetics
4. Arsenic (V) removal efficiency
Challenges
1. Not effective for As (III) without preoxidation
2. High cost if arsenic is primary target contaminant
3. Not suitable for POE systems due to corrosion and affordability
4. Requires proper attention and routine maintenance
5. Wastes 3-5 gallons of water for every treated gallon


Treatment options for central treatment systems

Coagulation / Filtration:
Advantages
1. Easy modification of existing system can be performed to increase arsenic removal
2. 95% removal of As (V)
Challenges
1. Not effective for As (III) without preoxidation
2. Performance decreases with higher and lower pH
3. Arsenic contaminated coagulation sludge may present a disposal issue
4. Requires well-trained operators

Lime Softening:
Advantages
1. Easy modification of existing system can be performed to increase arsenic removal
Disadvantages
1. May not be effective for high levels of arsenic where greater than 80% removal required
2. Secondary treatment may be required to treat high arsenic levels
3. Arsenic-contaminated coagulation sludge may present a disposal issue
4. Requires well-trained operators

Ion Exchange:
Advantages
1. Works well with filtration as a polishing step
Disadvantages
1. High sulfates and TDS will impact performance
2. Frequent regeneration may impact cost
3. Suspended solids and precipitated iron may clog the resin bed
4. Highly concentrated waste stream may present a disposal issue.

7. Q: Why consider a Point-of-Use approach?
  A:

Immediate protection from contaminated water. An abundance of water treatment professionals are available to assist in selecting an appropriate system to meet specific treatment and maintenance needs.

Simple maintenance, usually performed by the homeowner through cartridge replacement. Waste disposal of adsorption technologies are non hazardous and can be disposed with household waste

Lower cost. At $0.10 to $0.20/gal., POU treated water is more than 50 percent less than the cost of bottled water, which ranges from $0.75 to $2/gal. Initial capital costs range between $250-500. Annual operating and maintenance costs will average $30-50. Annual costs are minimized because only the water needed for consumption is treated.

Customized flexibility. POU systems can be custom designed, allowing the consumer the opportunity to address a range of concerns based on budget and preferences. It also creates flexibility to cost effectively upgrade the system should new cartridge-based improvements be commercialized. The customer has the choice to decide which aspects of his water are most important to him and focus a solution towards improving the quality of his drinking water based on his needs and budget.

8. Q: What questions to ask in selecting a POU/POE treatment system?
  A:

What level of arsenic is in the water? This factor will help determine the effectiveness of the system as well as the level of required maintenance.

What form of arsenic is in my water? Arsenic comes in both a pentavalent (AsV) and a trivalent (As III) state. Arsenic (III) is the harder to remove and more hazardous of the two. Not all treatment systems can remove both forms of arsenic and convert it to As (V) through oxidation with chemicals such as chlorine, potassium permanganate or ferric chloride, which can be dangerous to humans.

What is the water profile? Several characteristics of the water such as pH silicate level and temperature can effect the performance of a treatment system being considered, which may also make a pretreatment system necessary. This question is important for a small community system interested in using a POU solution for compliance.

How much water will be treated? Do I want to treat all of the water in my household or just my drinking water? This decision greatly will impact the cost of the treatment system. EPA data indicates that arsenic only is dangerous when ingested through consumption.

What type of waste is generated by the treatment system? Is there water waste? Is a hazardous material generated? Is disposal of the waste a problem?

How do I test for arsenic? There are several field test kit systems that can be used to determine the level of total arsenic present in the water. The use of these tests kits can help determine the level of treatment needed and ensure proper function of the treatment system once installed.

9. Q: What Research has been conducted on Arsenic?
  A:

During the 1940s when a standard for arsenic was first established, the key health effects of ingesting arsenic were believed to be limited to skin cancer and black foot disease. Since that time, extensive research has been done around the world linking arsenic to a wide range of health effects including both cancer and non-cancer causing illnesses.The majority of toxicity and epidemiology research on the topic has been performed outside of the United States, which has been a key factor in the controversy over which level of arsenic is safe for drinking water.

On April 23, 2001, the National Academy of Sciences (NAS) was directed by EPA to analyze the research conducted on the health effects of arsenic and make an appropriaterecommendation for the United StatesIn its analysis, NAS used research published through the fall of 1999. In a renewed effort to determine the appropriate level by the Bush Administration, the EPA again has turned to the NAS requesting an analysis of health effects research published since their last review. The NAS’s report is due in October 2001.

Research is continuing on the health effects of arsenic exposure.Currently, research by EPA is focusing on the cancer effects from low exposure to arsenic, arsenic toxicity in human tissues and the effects of dose and length of exposure to arsenic. Research by the University of California-Berkeley studies the effects of dose and cancer risks, nutritional and genetic susceptibility to arsenic effects, DNA analysis of tumors in arsenic-exposed populations and assessment of non-cancer effects from exposure to arsenic.

10. Q: What are the water quality parameters that need to be known before employing an iron oxide adsorption treatment solution?
  A: To effectively implement an iron oxide adsorption treatment solution a detailed water quality analysis is needed. The most important analyses are pH, As, As (III), SiO2, PO4, V, Fe and Mn.
• pH determines whether or not pH adjustment is recommended to improve the media’s adsorption capacity
• Total As determines the treatment capacity of the life of the media. As (III) may require longer EBCT.
• SiO2, PO4 and V are interferents that can reduce adsorption capacity
• Depending upon their levels, Fe and Mn could be removed simultaneously with As by the iron oxide media. At elevated levels, pretreatment for Fe and Mn removal is recommended and improves the adsorption process.

11. Q: Is there a timeline to implementing an arsenic removal treatment solution?
  A: Some specific applications might require lab and pilot testing before the full scale implementation of an arsenic removal treatment solution can take place. This process can take any where from 4 18 months to complete.

12. Q: What is the average length of a pilot program?
  A: Depending upon specific objectives, programs can last from 2 to 6 months.

13. Q: Are all iron oxide adsorptive media alike?
  A: All iron oxide arsenic removal media are not the same and should be evaluated based on media usage, product quality, availability and effect from interferences.
• Media Usage includes product density, adsorption capacity and compaction.
• Product Availability includes production capability and freight based on bulk density.
• Product Quality includes particle structure, friability, decomposition and handling.

14. Q: What are the options for arsenic treatment?
  A: Before even considering the available options, a municipality might be able to avoid treatment by blending available water sources to reduce the overall arsenic contamination level. Another option is to abandon the current water source and review options for obtaining a completely new source that is arsenic-free. But if operational changes cannot be implemented, arsenic removal treatment options must be evaluated.

Current arsenic removal treatment options include ion exchange, activated alumina, reverse osmosis, coagulation/microfiltration and adsorption. When the EPA released the federal regulation it listed coagulation filtration, alumina adsorption, ion exchange and reverse osmosis as the Best Available Technologies (BATs), but since it can take up to ten years to develop a regulation from conception to final ruling, BAT designation can’t always keep up with commercially available technology. For example, iron oxide media, are not listed as BATs, but commercially available products using adsorption technology are viable treatment options for arsenic in drinking water.

15. Q: What is the potential role of iron oxide adsorption as municipalities continue to evaluate treatment technologies in their efforts to meet the January 2006 deadline?
  A: Adsorption, especially technologies using iron oxide media, will continue to be at the forefront of arsenic treatment options that a municipality evaluates in its efforts to comply with the 10 ppb arsenic MCL. Adsorption technology is proven across varying water quality conditions and offers a treatment solution that is simple and cost effective. This isn’t to say that under certain, difficult water quality conditions, that a competitive technology wouldn’t be more beneficial, it’s just to say that adsorption will be able to treat the majority of arsenic contamination problems in the U.S.