TR SUPPLEMENTARY REQUIREMENTS FOR THE ACCREDITATION OF CONTINUOUS AMBIENT AIR QUALITY MONITORING STATIONS

Transcription

1 SUPPLEMENTARY REQUIREMENTS FOR THE ACCREDITATION OF CONTINUOUS AMBIENT AIR QUALITY MONITORING STATIONS Approved By: Chief Executive Officer: Ron Josias Senior Manager: Christinah Leballo Reviewed By: Testing STC Members Date of Approval: Date of Implementation: SANAS Page 1 of 12

2 CONTENTS 1. Purpose and Scope Definitions and References Introduction Requirements Bibliography: APPENDIX A: Criteria for Representativeness of Air Quality measurements and Statistics ADDENDUM 1: Amendment Record SANAS Page 2 of 12

3 1. Purpose and Scope The purpose of this document is to stipulate additional technical requirements to ISO/IEC 17025:2005 for the accreditation of continuous ambient air quality monitoring stations. 2. Definitions and References 2.1 Normative References: National Environmental Management: Air Quality Act, 2004 (Act 39 of 2004) National Framework for Air Quality Management in the Republic of South Africa, 2007 ILAC G8:2009 Guidelines on the reporting of compliance to specifications PM 01 SANAS Policy Manual A 01 References, Acronyms and Definitions R80 Proficiency Testing Requirements for Testing laboratories 2.2 Useful References: Quality Assurance Handbook for Air Pollution Measurement Systems (US EPA 600/ ) (Red Book) including volume IV, Meteorological Measurements Version 2.0 (Final) WHO Air Quality Guidelines for Air Quality (2000) and Global Update (2005) USEPA s list of reference and equivalent air quality monitoring methods and equipment can be found at The reference methods are described in detail in Appendix A to Section 50 of Chapter 40 (Environmental Protection) of the USA s Code of Federal Regulations (40CFR50 App. A). The current set of ambient air quality standards in the USA can be found at The current set of EU air quality guidelines can be found at Definitions: 3. Introduction Continuous ambient air quality monitoring station a station established for long-term monitoring of contaminant levels (e.g., sulphur dioxide (SO 2 ); hydrogen sulphide (H 2 S), nitrogen monoxide (NO); nitrogen dioxide (NO 2 ); ozone (O 3 ); total oxides of nitrogen (NO x ); particulate matter (PM 10 and PM 2.5 ) ; carbon monoxide (CO); benzene or toluene) using South African reference methods or equivalent methods. The veracity of data produced from continuous ambient air quality monitoring systems play a key role in making informed decisions about the measures required to protect the health and safety of the population and the environment as outlined in South African national legislations and the national framework concerning air quality. In order for data to be useful, it must be reliable. The internationally accepted standard, ISO/IEC 17025:2005, outlines the minimum requirements for a facility to establish technical competence to ensure quality results are produced that are reliable. The benefit of accreditation is that the facility is evaluated for its technical competence to produce reliable data consistently by an independent third party consisting of competent peers. Accreditation bodies that are signatories to the ILAC mutual recognition arrangement provide the further advantage that accredited data can be compared or accepted on an international basis. SANAS Page 3 of 12

4 4. Requirements 4.1 Monitoring Objectives A facility shall outline the objective(s) of monitoring in their quality system. Establishing a monitoring objective is the fundamental step in developing a monitoring programme, because all subsequent decisions will be based on why the monitoring is being undertaken The most common reasons for monitoring include: determining the level of contaminants in an area to compare with standards and guidelines; reporting on the state of the environment; obtaining exploratory data; conducting air quality research; obtaining data for air quality modelling; providing air quality information for policy or strategy development; and assessing the effectiveness of policy based on air quality trends. 4.2 Monitoring Plan A facility shall formulate a monitoring plan based on the objective(s) of the monitoring The monitoring plan shall also include details of: Which species to monitor? In many cases this may be obvious, based on known emission sources in the area, but in other cases it merits careful consideration. Once the target contaminant has been identified, in what form should it be monitored? For example, total hydrocarbons or individual (speciated) hydrocarbons? Total particulate matter or a specific size fraction? Is further analysis required? How to sample? Both the type of sampling and the analytical method need to be considered. Method selection involves an appraisal of cost versus performance; the latter includes the limits of detection, sensitivity, speed of instrument response, susceptibility to interfering species and the overall uncertainty of the measurement. Consider the objective(s) of monitoring and choose appropriate methods and equipment. Where to sample? The decisions around where to locate a monitoring site are based on the objectives of monitoring. The siting of an air quality monitoring station has a profound effect on the resulting measurements of contaminant levels and on achieving monitoring objectives. Will the site measure peak or background concentrations? What atmospheric reactions affect the formation/destruction of the contaminant to be monitored? Note: Refer to Table 12 and Table 24 of the National Framework for Air Quality Management in the Republic of South Africa, 2007 for compliance monitoring guidance. SANAS Page 4 of 12

5 4.3 Monitoring Station Design and Site (Probe) Location and sampling system For compliance monitoring refer to the National Framework for Air Quality Management in the Republic of South Africa, 2007 and National Ambient Air Quality Standards (Government Gazette No of 24 December 2009) The minimum requirements for station design and sampling system are: Station design for gaseous and particulate analysers a) Ambient analysis equipment must be designated as equivalent methods by the EPA or other internationally recognised bodies for example USEPA, TÜV or EN. b) The enclosure must be weatherproofed and temperature controlled. c) The station must be secure and allow only restricted access. d) The station must be clear of tall obstructions that may impede measurements. e) Any nearby non-representative sources must be considered. f) The inlet to the probe must be located away from tall buildings or obstructions. The distance between the inlet probe and the obstruction must be at least twice the height that the obstruction protrudes above the inlet of the probe. g) Air flow must be unrestricted in an arc of at least 270 around the probe inlet and the predominant wind direction for the season of greatest pollutant concentration potential included in the 270 arc. h) If the probe is located on the side of a building, 180 clearance is required. i) The sampler inlet should be placed at least 20 m from the drip line of trees. In situations where trees could be classified as an obstruction, paragraph (f) above applies Temperature and Humidity a) A monitoring station requires a suitable environment with specific environmental conditions. b) Cognisance must be taken of the ambient external conditions with regard to dew point. c) Shelter temperature must be controlled at 25 C ± 5 C and records kept to verify this. d) Should the temperature rise to above 30 C, data must be flagged and evaluated for representativeness Sampling lines for gaseous components a) In order to ensure adequate sampling response time the sampling line between the inlet manifold and analyser shall be Teflon. b) The sampling line must be in one piece and no additional traps or filter mechanisms are allowed. It should preferably be no longer than 2 meters in length from the manifold to the analyser. c) The outer diameter of the sampling lines must be at least 6 mm. SANAS Page 5 of 12

6 d) The sample train should be designed with a minimum of kinks, joints, reducers, etc. to allow for free flow of the sample to the analyser Sampling manifold for gaseous components a) The sampling manifold must be made from borosilicate glass or FEP Teflon. b) The sample residence time within the manifold must be less than 20 seconds. The sample residence time needs to be verified at regular intervals and verification records must be kept. c) The sample manifold should be designed for easy cleaning and cleaning should be carried out at least monthly. Records should be kept of when cleaning of the manifold was performed. d) The sample manifold and system must be routinely checked for leaks and relevant records kept. e) The entrance to the probe should be located 3 to 15 m above ground level. f) If located on the side of a building, it should be on the windward side relevant to the prevailing winter wind direction. g) The probe inlet should be at least 1 m vertically or horizontally away from any supporting structure and also away from dirty, dusty areas. h) If the inlet probe is located on top of a roof or other structure, it must be at least 1 m from walls, parapets, etc. i) Inlet sample material must be manufactured from borosilicate glass or FEP Teflon or their equivalent non-reactive compounds Ambient Particulate Matter Analysers 4.4 Meteorological Requirements a) All routine analyser performance checks must be recorded. b) The frequency of calibration/verification of the analyser shall be documented and be in line with national and international requirements. c) The different monitoring technologies, used to continuously monitor particulate matter, are prone to positive or negative biases when compared to EN12341 (the South African Reference Method). As these biases are site specific, experimental work or a literature review must be undertaken (for the specific equipment at the specific monitoring site) to determine the correction factor to be applied that will ensure equivalence to EN12341, and that will adequately protect the exposed population and environment Meteorological conditions are important in assessing the impacts of sources on surrounding areas, because they dictate the transport and dispersion of contaminants in ambient air. The specifications for meteorological parameters must suit the intended purpose for monitoring as outlined in the EPA Quality Assurance Handbook Volume IV The minimum meteorological parameters to be measured and reported at the same frequency as the primary pollutants are: wind speed, wind direction and ambient temperature: SANAS Page 6 of 12

7 Note: The use of the Cartesian coordinate system is recommended, whereby data is converted to its x and y components. This data can then be accumulated in a vector form. This solves averaging and unweighted direction problems. Results may subsequently be converted to polar coordinates, if required Desirable additional measurements include humidity, solar radiation, barometric pressure and rainfall, as well as a temperature profile for atmospheric stability purposes Specific siting requirements: The site must meet the requirements of the EPA Quality Assurance Handbook (Vol IV) Required time resolution: Data should be collected at the same minimum time resolution as air quality data; Resolution should be at least hourly Period of monitoring: For atmospheric modelling and trend analysis, a minimum of one year s data is recommended. Everything that is installed must be calibrated to a national reference standard where such a standard exists. Monitoring stations need to keep a record of maintenance and calibration of equipment. The calibration of wind direction and speed monitoring equipment shall be undertaken after repair otherwise annually and documented. All wind direction sensors must be aligned to true north or the data corrected accordingly. Note: Wind direction, by convention, is the direction the wind is blowing from and is quoted with reference to true north (not magnetic north). An exception to this is meteorological data collected for oceanographic monitoring purposes. In this case, the wind is recorded in the direction it is blowing towards. Care should be taken to determine the meteorological wind convention when using data collected from the marine environment. The preferred reporting unit for wind speed is metres per second (m/s). 4.5 Calibration Requirements for gaseous components Calibration and maintenance of monitoring equipment is an important part of every monitoring programme. How frequently should calibration be undertaken? What documentation is required? What procedures will ensure the efficient and smooth operation of monitoring equipment? a) Each monitoring station is required to have quarterly on-site dynamic multipoint (minimum zero/span and three intermediate point checks) and a minimum of two-weekly zero/span checks by means of an accurate known concentration undertaken on each gas analyser. SANAS Page 7 of 12

8 b) These quarterly and two-weekly zero/span checks and any actions taken as a result thereof, must be clearly documented as part of the quality documentation. These results will be used to assess the organisation s ability to perform their monitoring activities within the scope of their accreditation. c) The start and end time for span/ zero checks and calibrations must be recorded d) The requirements for analysers to be dynamically calibrated on site are as follows: i. when analyser is initially installed; ii. every three months; iii. if any repair is done on the analyser; iv. if tolerances of zero/span checks are not met; v. if analyser is relocated. e) At least, one of the four quarterly calibrations of the equipment shall be undertaken by an accredited calibration laboratory. f) The facility must participate in inter-laboratory comparisons at pre-determined intervals and a programme covering 18 months must be available. g) Portable calibrators that are transported shall be checked before and after use or at documented determined intervals, against the relevant reference standard(s). h) Certified reference gases shall be used for in-house calibrations at predetermined intervals. 4.6 Data Management Protocols It is important to ensure that air quality data is properly validated and managed after it is obtained The facility shall maintain records in accordance with the methods used, the quality system and the retention period as required by legislation. What data quality assurance processes are in place? What supplementary data needs to be collected? Other information may be relevant to the study (e.g. meteorological conditions, process data and traffic flows). 4.7 Accredited Data a) A copy of the raw data shall always be available and shall be stored at one minute intervals. b) A record and motivation must be kept of any corrections/alterations done to the raw data including zero/span checks. c) All multiplication factors/algorithms/manipulations on the data must be recorded and reported. d) Accurate and detailed operations on site, e.g. changes to analyser settings, must be reported in a site operations report. e) Data must be kept for a minimum of three years There will be only one level of accreditation for ambient air pollution monitoring stations. SANAS Page 8 of 12

9 a) If data is suspect it may not be used until an investigation has shown it to be valid in terms of the scope of accreditation. b) Stations should supply data for 90% (per parameter) of the monitoring period (not less than three months) within the accuracy of their accreditation. Note: Where data captured is less than 90%, reasonable cause shall be documented. c) See Appendix A (Criteria for Representativeness of Air Quality measurements and Statistics) 4.8 Data Acquisition (Logging Devices) a) Output from the analyser must be recorded. b) The accuracy of the logging device must be verified annually. c) Hourly mean concentrations must be generated. d) The logger must be able to scan at minimum 10 second intervals with a minimum scan period of 1 hour. e) The calculation of the mean requires data points to be collected for a minimum of 40 minutes uninterrupted. f) The mean and other statistical calculations shall be validated. 4.9 Reporting of data & compliance to specifications When data is reported, the temperature and pressure at which the analyser was last calibrated must be indicated on the test report. Any statement of compliance to specifications shall be based on ILAC G8:2009. How will data be stored and reported? What time format should be used? How will exceedences be determined and reported? 4.10 Staff Competence The facility shall have access to people who have competencies in, or shall have staff who have amongst other competencies, competence in: air quality legislation; air quality monitoring; equipment operation and maintenance provided by equipment manufacturers; conducting of in-house calibrations where applicable; ISO/IEC 17025:2005; internal auditing of the quality system and technical activities of the facility Internal Audits The facility shall ensure that all aspects of their quality system including their testing activities and where applicable their calibration activities are subject to an internal audit to confirm compliance to ISO/IEC 17025:2005 requirements, SANAS requirements and any relevant legislation. All monitoring stations shall be audited against SANAS TR07 requirements Supplementary Requirements for the Accreditation of Continuous Ambient Air Pollution Monitoring Stations within a 12 month planned audit timeframe. Corrective actions taken at a specific station shall be investigated for its applicability to other stations Proficiency Testing The facility shall maintain a Proficiency Testing plan as outlined in SANAS R80 Proficiency Testing Requirements for Testing Laboratories. SANAS Page 9 of 12

10 5. Bibliography: Ministry for the Environment Good Practice Guide for Air Quality Monitoring and Data Management Wellington: Ministry for the Environment, Government of New Zealand. SANAS Page 10 of 12

11 APPENDIX A: Criteria for Representativeness of Air Quality measurements and Statistics Representative Calendar Statistic Sampling Time Period Basis of Statistic or Requirement Number of Representative Periods Required Year Any 4 Representative calendar quarters Quarter 24-Hour Based on daily sample 3 Representative months < 24-Hour Based on daily statistic or; Based on hourly analysis 69 or more representative calendar days 1643 or more hours Month 24-Hour Based on daily sample 4 or more 24-hour samples <24-Hour Based on daily statistic; or Based on all hourly analysis; or Based on all 2-hour samples; or Based on all 3-hour samples Day 1-Hour Based on 1-hour samples 23 or more representative calendar days 548 or more hours 274 or more 2-hour samples 183 or more 3-hour samples 6 or more hours in each 1/3 day (hours 0 thru 7, 8 thru 15, 16 thru 23), and missing no more than 2 consecutive hourly samples 2-Hour Based on all 2-hour samples 9 or more samples 3-Hour Based on all 3-hour samples 6 or more samples 24-Hour N Based on daily sample Number of samples needed Mean of N or more hourly samples Hour Period 8 6 or more hourly samples 6 5 or more hourly samples 4 3 or more hourly samples 3 3 or more hourly samples 2 2 or more hourly samples 1 30 minutes or more hourly samples 22 but no more then 26 hours of sampling SANAS Page 11 of 12

12 ADDENDUM 1: Amendment Record Proposed By: Section Change FM Entire document FM 1. Purpose and Scope 2. Definitions & References Realign to legislation Changed from: The purpose of this document is to identify technical requirements for accreditation and is applicable to all SANAS accredited Continuous Ambient Air Pollution Monitoring Stations. Added Normative References, Useful References and Definitions 3. Added Introduction 4. Added 4.1 and 4.2 requirements 4.3 Added: and sampling system to clause heading. Added 1 st 2 paragraphs of clause (a) Added: internationally recognised bodies for example USEPA, TUV or MCERT. 4.3 (g) Added and cleaning should be carried out at least monthly 4.4 Added clause Added 1 st 2 paragraphs, and clause 4.5 (e) 4.6 Changed heading from Management of Data to Data management Protocols. Added 1 st 3 paragraphs, and and shall be stored at one minute intervals to first bullet point 4.9 Added point (c) 4.8 Changed heading from Logging Devices to Data acquisition 4.8 (f) Added against software 4.10 Added & compliance to specifications to clause heading. Added everything besides the 1 st sentence 4.11 Added Clause 4.12 Added Clause 4.13 Added Clause Added Bibliography Added Appendix A STC 2012 June 1 Removed provide supplementary and added stipulate additional 2.3 Added South African reference methods or equivalent methods Note page 4 Changed wording of paragraph to include the National Framework for Air Quality Management The paragraph was re-organised into sub-paragraphs grouping similar issues together Reference to EPA Handbook was added Note on page Paragraph of version 2 was made a note The paragraph content was deleted and reference to EPA was inserted instead Paragraph c was added, paragraph e was amended and f to h added 4.9 Paragraph 4.9 in version 2 was deleted SANAS Page 12 of 12