COMPASS09 Annual Conference of Compass Informatics

1. COMPASS09 Annual Conference of Compass Informatics

2. Use of Geographic Information Systems (GIS) to Calculate the Assimilative Capacity of Rivers to Receive Proposed Discharges Vivienne Kelly Informatics & Reporting Office of Environmental Assessment t: 053-9160612 e: v.kelly@epa.ie

3. Presentation Outline • Introduction to Assimilative Capacity • Calculating Assimilative Capacity & Concentrations • Integrating Data Sources • Demonstration of GIS Assimilative Capacity Tool

4. Our Vision Aim: To develop environmental management systems that assess and report on environmental quality using integrated data from multiple data sources to provide more intelligence to data users see and to increase the efficient use of EPA resources. Systems Developed: • Assimilative Capacity Tool • Risk Assessment Tool (Landfills, Quarries & Mines)

5. Assimilative Capacity • What is assimilative capacity? … the ability of a body of water to cleanse itself; its capacity to receive waste waters or toxic materials without deleterious effects and without damage to aquatic life or humans who consume the water. • How is it calculated? • Simple calculation: (AC = (cmax – cbackground) x (F95 or DWF) x 86.4) • Environmental Quality Standards (EQS) (cmax) • Background Chemical Monitoring (cbackground) • Hydrometric Flow (95%iles & DWF) • EPA Role? When assessing proposed discharges from IPPC, Waste and Waste Water Discharge Applications, the EPA must determine the capacity of a waterbody to receive the discharge and the potential environmental impacts.

6. Q2: What is the concentration following the discharge? UWWTP River Q1: What is the capacity upstream of the discharge? Q3: What proportion of the capacity has been absorbed as a result of the discharge? Questions to Ask

7. Calculations • Assimilative Capacity: • Non Toxic Substances  AC = (cmax – cbackground) x F95 x 86.4 • Dangerous Substances  AC = (cmax – cbackground) x DWF x 86.4 • The capacity of a water body is calculated in kg/day Variables: AC = Assimilative Capacity Cmax =     Maximum permissible concentration (EQS) Cbackground =     Background concentration in river F95 = 95%ile flow in the river (m3/sec) DWF = Dry Weather Flow in the river (m3/sec)

8. (Cback x Vflow) + (Ceffluent x Veffluent) Cfinal = (Vflow + Veffluent) (Cmax - Cback) - (Cmax - Cfinal) % AC Absorbed = x 100 (Cmax - Cback) Other Calculations • Resultant Concentration: • Capacity Absorbed: Cmax =     Maximum permissible concentration (EQS) Cfinal =     Concentration in river after discharge of effluent Cback =     Background concentration in river Ceffluent =     Treated effluent concentration Vflow =     Volume of flow in river (95%ile or DWF – m3/sec) Veffluent =     Volume of effluent (m3/sec)

9. Waste Water Discharge Licence Substances Total Calculations = 93 Per Discharge Point Total Substances = 31

10. Assimilative Capacity WebGIS Tool • The Assimilative Capacity Tool is a web based GIS application designed to allow licence inspectors to calculate the capacity of rivers and the surrounding environment to receive pollutants from waste water treatment discharges. • Function: • Determine the capacity of waterbodies to receive specific pollutants from proposed discharges. • Determine the potential impacts to the surrounding environment. • Improve the use of resources & produce better response times. • Support decision making.

11. Model Concept AQUARIUS Discharge Point Hydrometric Station Monitoring Station River Flow Direction Water Quality Data ENGINE Hydro Flow Data Calculation Hydrometric Data Proposed Discharge Proposed Limit Assimilative Capacity at Proposed Point of Discharge Run Engine

12. Integration of Internal & External Data

13. Other UWWTP’s Conservation Data River Data Toolbar Select Assimilative Capacity Tool Report Window Appears Summary of local EPA Monitoring Stations With New EQS Capacity is not Exceeded. EQS Exceeded Prior to Discharge Select Environmental Report Downstream Monitoring Point Upstream Monitoring Point Table of Contents User Selects Required Report Zoom to Area of Interest User Selects New EQS, Saves and Re-runs Report Zoom to Area of Interest Option to Change EQS Summarry Information on Discharge Map of Discharge Hydro Data Click to Highlight Station on Map Select Discharge Point Discharge Point Water Quality Up & Down Stream Click Next Assimilative Capacity Tool Demonstration Demonstration

14. Caveat • Decision Support Tool • Indication of waterbody capacity, not absolute rule • Inspectors must have full understanding of EQS for a site and ensure appropriate data used in any calculation • All borderline cases should be examined in full

15. Improved Resource Use • EPA Aim: To increase the efficient use of EPA resources • Manual Effort: 4-6 days • No. of Discharges: 177 • Approx. Time to Calculate Manually: 3yrs • Total Time using AC Tool: 4 days

16. Development Team EPA Team: • Breen Higgins • Gavin Smith • Fiona O’Rourke • Deirdre Kirwan • Tom Stafford • Ozan Emem • Jason Larkin • Claire Byrne • Aisling McElwain • George McHugh Compass Team: • Ken Dowling • Pavel Janda • Seth Girvin • Maurizio Taddei • Mick Lennon THANK YOU

17. COMPASS09 Annual Conference of Compass Informatics