Arsenic Rule Compliance. Purpose. Learning Objectives. Arsenic is a primary drinking water contaminant, regulated by USEPA.

Transcription

1 Arsenic Rule Compliance Workshop developed by RCAP/AWWA and funded by the USEPA Purpose Arsenic is a primary drinking water contaminant, regulated by USEPA. This workshop will provide small systems with the information needed to learn how to achieve compliance. Learning Objectives As a result of this lesson, you will be able to: 1. Describe the importance of the Arsenic Rule in protecting public health 2. Determine if a water system is in compliance with the rule 3. Use proper technique to collect a sample for arsenic testing. 4. Communicate arsenic-related information to customers 5. Evaluate options for attaining compliance 6. Access technical and funding guidance Developed by AWWA in partnership with RCAP and funded by USEPA, Published

2 Agenda Background and the Arsenic Rule Sampling and Compliance Activity Compliance Determination Compliance Options Non-Treatment Treatment Summary Arsenic Naturally occurring element present in the environment in rocks, soil, air, plants, and animals Product of some industrial activities Can be present in surface water or groundwater sources, although more prevalent in groundwater. Realgar is an example of an arsenic containing mineral ( als/mineralogy) Arsenic Chemistry Arsenic may be present in water in two different forms: Arsenic (III) and Arsenic (V) Total arsenic is a measurement of both forms of arsenic The form of arsenic present can impact treatment effectiveness Developed by AWWA in partnership with RCAP and funded by USEPA, Published

3 Arsenic Regulations Arsenic is regulated under the USEPA Arsenic Rule due to health concerns associated with long-term exposure, including cancer. Arsenic Rule Finalized in 2001 Objective to improve public health by limiting exposure to arsenic. Applies to all community water systems (CWS) and non-transient non-community water systems (NTNCWS). Arsenic Rule Sets MCL for total arsenic at 10 g/l, with an MCLG of 0. Includes components for: Sampling, monitoring, and compliance determination Public communication language for CCR Developed by AWWA in partnership with RCAP and funded by USEPA, Published

4 Arsenic Rule Timeline 2001 Arsenic Rule promulgated 2002 Arsenic Rule effective 2002 CCR language must be used as required by the rule g/l MCL effective Initial sampling completed Knowledge Checkpoint What type of systems must comply with the Arsenic Rule? What is the MCL for arsenic? Sampling for Arsenic Samples collected at each entry point to the distribution system Sample frequency (if initial sample <MCL): Surface water/gwudi Annual sample Groundwater Every 3 years Sample frequency (if initial sample >MCL): Quarterly samples Developed by AWWA in partnership with RCAP and funded by USEPA, Published

5 Sampling for Arsenic Collect sample and send to certified lab for analysis Samples typically collected in plastic bottles, which may contain nitric acid preservative If pre-packaged with preservative, do not rinse Take steps to avoid contamination, and follow any specific instructions provided by the lab Sampling for Arsenic Failure to sample, not sampling every required sampling point, or not reporting results to the primacy agency on time may result in a monitoring and reporting violation Follow up on any results that are submitted automatically to the primacy agency! Be aware of units! Knowledge Checkpoint If arsenic is present at concentrations greater than the MCL, how often must systems sample for arsenic? Developed by AWWA in partnership with RCAP and funded by USEPA, Published

6 Compliance Determination Sample results above the MCL will result in quarterly monitoring Initial confirmation sample may be required Arsenic Rule compliance is based on a running annual average Running Annual Average Calculation R1 + R2 + R3 + R4 4 = RAA Activity #1 Calculate RAA Determine compliance status Developed by AWWA in partnership with RCAP and funded by USEPA, Published

7 Activity Part I A groundwater utility sampled for arsenic for the past 4 quarters and has reported the following results to the state: mg/l mg/l mg/l mg/l Is this system in compliance with the Arsenic Rule MCL? Activity - Explanation To calculate the RAA for the system: RAA = (0.030mg/L mg/L mg/L mg/L)/4 RAA = mg/l The system is not in compliance with the Arsenic Rule MCL Activity Part II The same groundwater utility sampled for arsenic during a 5 th quarter and has obtained the following result: mg/l mg/l mg/l mg/l mg/l (5 th quarterly sample) Is this system in compliance with the Arsenic Rule MCL? Developed by AWWA in partnership with RCAP and funded by USEPA, Published

8 Activity - Explanation Encourage attendees to calculate the RAA for the system: RAA = (0.012mg/L mg/L mg/L mg/L)/4 RAA = mg/l The system is still not in compliance with the Arsenic Rule MCL Reporting and Notification Violations must be reported according to Arsenic Rule Requirements. There are also specific requirements for the language used in the CCR pertaining to arsenic. Reporting and Notification Monitoring and Reporting Report to primacy agency within 48 hours Public notification within one year (may be in CCR) MCL violation Report to primacy agency within 48 hours Public notification within 30 days Developed by AWWA in partnership with RCAP and funded by USEPA, Published

9 Arsenic Results > mg/l CCR Language Requirements > mg/l but < mg/l mg/l Required Language Heath Effects Statement must be included in CCR to read Some people who drink water containing arsenic in excess of the MCL over many years could experience skin damage or problems with their circulatory system, and many have an increased risk of getting cancer. Educational Statement in CCR to read similar to While your drinking water meets EPA s standards for arsenic, it does contain low levels of arsenic. EPA s standard balances the current understanding of arsenic s possible health effects against the cost of removing arsenic from drinking water. EPA continues to research the health effect of low levels of arsenic, which is a mineral known to cause cancer in humans at high concentrations and is linked to other health effects such as skin damage and circulatory problems. No special language is required Activity Based on the water system previously discussed (RAA of mg/l), what public notification actions must be completed? Activity The system is out of compliance with the Arsenic Rule MCL (0.017 ml/l). Report results to primacy agency within 48 hours Public notification within 30 days Include Health Effects statement in the water system s CCR Developed by AWWA in partnership with RCAP and funded by USEPA, Published

10 Compliance Options If arsenic levels in a water source are higher than the MCL, the system will need to take action to achieve compliance. Non-treatment options Treatment options Non-Treatment Options Change in source water Partner with other water systems Connect to an existing system Consolidate with other utilities Purchase water from another system Source Water Changes Change to a source water that is low in arsenic or blend with a low arsenic source Considerations: Water availability/water rights Presence of contaminants in new source that may require treatment Switch to a surface water source requires filtration Developed by AWWA in partnership with RCAP and funded by USEPA, Published

11 Partnerships with Other Systems Combining resources or interconnecting with neighboring systems to provide safe water Considerations: Feasibility of location Administration Water quality Operations Knowledge Checkpoint What are some non-treatment options for Arsenic Rule compliance? Treatment Options Activated alumina (BAT) Enhanced lime softening (BAT) Anion exchange (BAT) Coagulation/filtration (BAT) Oxidation/filtration (BAT) Reverse osmosis (BAT) Point of use (POU) devices Developed by AWWA in partnership with RCAP and funded by USEPA, Published

12 Treatment Considerations Form of arsenic As(III) vs. As(V) Concentration of arsenic Water ph Raw water quality/competing ions Pre-existing treatment Treatment Considerations Operational complexity Costs capital and operational Waste/residual production Sidestream treatment or blending System placement centralized versus localized treatment Activated Alumina Water is run through a packed column of fine grained, absorptive media to remove arsenic Media replaced or regenerated when exhausted EPA Small System Arsenic Compliance Guide Developed by AWWA in partnership with RCAP and funded by USEPA, Published

13 Enhanced Lime Softening Arsenic is removed by attaching to particles formed during the lime softening process Particles are filtered out to remove arsenic Most suitable for systems already using the process for softening Ion Exchange Arsenic is removed by exchange with an ion exchange resin Water flows through a packed column of ion exchange resin Resin is regenerated when its exchange capacity is exhausted Coagulation/Oxidation & Filtration A coagulant (iron/aluminum based) or oxidant (air/chlorine/permanganate), enabling the arsenic to form a precipitate which can be removed using filtration Filters for Arsenic Removal ( Developed by AWWA in partnership with RCAP and funded by USEPA, Published

14 Reverse Osmosis A membrane with a very small pore size provides a physical barrier against the passage of arsenic ions RO Filters ( Point of Use Devices Treatment devices that are placed at individual customer taps Considerations Water system is responsible for inspection and maintenance, which may include entering residences Factor Arsenic Treatment Summary Activated Alumina Modified Lime Softening Ion Exchange Coagulation or Oxidation and Filtration Reverse Osmosis BAT Yes Yes Yes Yes/No Yes No Operator Skill Level Waste Low High High Medium, High Spent media, backwash water Backwash water, lime sludge Spent resin, brine, backwash water Backwash water, sludge Cost Medium Low Medium Low to Medium Source USEPA Arsenic Treatment Technology Evaluation Handbook for Small Systems Medium Reject water High POU Devices Varies Varies Varies Developed by AWWA in partnership with RCAP and funded by USEPA, Published

15 Knowledge Checkpoint What are some considerations that must be taken into account when selecting a treatment-based compliance option for arsenic? Compliance Strategy Selection EPA decision trees can help to provide guidance Treatment or non-treatment Most applicable treatment process Basic process design considerations EPA Decision Tree: Non-Treatment Source USEPA Arsenic Treatment Technology Evaluation Handbook for Small Systems Developed by AWWA in partnership with RCAP and funded by USEPA, Published

16 EPA Decision Tree: Treatment Source USEPA Arsenic Treatment Technology Evaluation Handbook for Small Systems Activity - Discussion Our groundwater system that is out of compliance is in the process of determining the best means for them to achieve compliance. They have a surface water source available to them that is low in arsenic They have an existing lime softening facility at the water system to remove hardness What can this system do to achieve compliance? Compliance Strategy Selection Evaluation of treatment alternatives should include bench and/or pilot scale testing of selected treatment methods Confirms treatment effectiveness Helps to estimate full scale design and cost Primacy agency or consultant guidance recommended Primacy agency approval is required before any source or treatment process change Developed by AWWA in partnership with RCAP and funded by USEPA, Published

17 Summary The Arsenic Rule protects public health by reducing exposure to arsenic Sampling is required to determine compliance status Non-treatment and treatment based alternatives can help systems achieve compliance Resources EPA Arsenic Rule resources ( a/arsenic/index.cfm): Arsenic Rule Quick Reference Guide Arsenic Rule Small Systems Compliance Guide Arsenic Treatment Technology Evaluation Handbook for Small Systems Financial assistance information Developed by AWWA in partnership with RCAP and funded by USEPA, Published