Low cost method for determining occurrence Integraci de

Low cost method for determining occurrence Integració de legislació ambiental d'aigües i de gestió and of combined sewerresiduals overflows de les duration estacions depuradores d’aigües A. Montserrat, O. Gutierrez, M. Poch, Ll. Corominas Ll, Acuña V, Ginebreda A, Poch M 7 th International Conference on Sewer Processes and Networks (28 -30 Sep 2013)

Table of contents • • • INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS 2

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS PROBLEM STATEMENT • Combined sewer overflows (CSO) are a threat for the environment EPA 3

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS CSO legal framework ØUWWTD (1991) – Dot not precise control measures ØWFD (2000) – Requires good quality for waters ØUpdating of UWWTD transpositions to account for CSOs (e. g. Real Decreto 1290/2012) MONITORING 4

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Reviewed CSO monitoring methods Visual inspections Conductivity meter Level sensor Water quality sensor Flowmeter 5

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Reviewed CSO monitoring methods MAIN DRAWBACK: TOO EXPENSIVE TO MONITOR THE ENTIRE CSO NETWORK 6

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS THE METHOD Principle: temperature differences between the sewer gas phase and the CSO 7

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Materials & installation setup Tº sensor Waterproof casing 45€ per unit Optic data reader Waterproof casing 240€ 3 -minutes frequency logging interval -> 120 days storing data 8

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Materials & installation setup 9

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Case-study La Garriga village (16. 000 inhabitants) Barcelona Besòs river basin 10

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Case-study La Garriga CSS 370 Ha drainage area 7. 3 km long pipes Ø 300 -800 mm Flow direction 13 weirs studied: - 6 transverse w. - 7 side-flow w. 11

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Case-study La Garriga CSS 370 Ha drainage area 7. 3 km long pipes Ø 300 -800 mm Flow direction 13 weirs studied: - 6 transverse w. - 7 side-flow w. TOTAL MATERIAL INVESTMENT 924€ 12

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Method validation for one single weir 13

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Method validation for one single weir 1 h CSO 14

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Types of temperature responses 3 categories of temperature response were defined 15

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Method effectiveness assessment for the entire CSO network EP = (Category 1 responses + Category 2 responses) / (Category 1, 2, 3 responses) * 100 For 1 year period, 57 rainfall episodes, 13 weirs: 723 responses 16

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Method effectiveness assessment for the entire CSO network For 1 year period, 57 rainfall episodes, 13 weirs: 723 responses 17

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Method effectiveness assessment for the entire CSO network Low effectiveness closely related to the characteristics of the weir CSO 13 EP: 49% CSO 9 EP: 40% CSO 11 EP: 54% Stuck water in the structure High turbulence in the sewer pipe Sensor in contact with the water in dry conditions 20

INTRODUCTION THE METHOD RESULTS CASE-STUDY CONCLUSIONS Characterization of the La Garriga CSS Looking for the critical weirs Weir CSO 1 CSO 2 CSO 3 CSO 5 CSO 6 CSO 7 CSO 8 CSO 10 CSO 12 Total Nº CSOs Total CSO duration (min) Mean CSO duration (min) 43 898 21 45 660 15 64 1214 19 72 2137 30 56 1261 23 103 1788 17 47 993 21 70 1410 20 43 870 20 Nº of times in Position 1 1 1 5 3 1 15 4 11 0 Nº of times in Position 2 0 2 2 3 4 10 5 8 1 Nº of times in Position 3 3 8 4 4 2 7 3 3 210

INTRODUCTION THE METHOD CASE-STUDY RESULTS CONCLUSIONS Conclusions • A low-cost method to quantify occurrence and duration of CSOs was developed • The method was validated, and high effectiveness obtained in most cases • The effectiveness was affected by some physical characteristics of the weir • Highly valuable data was obtained with a minimal investment of 924€ • The method offers potential applications Science of the Total Environment 463– 464 (2013) 904 – 912 22

Acknowledgements ENDERUS (CTM 2009 -13018) Juan de la Cierva (jci-2009 -05604) Eco. Ma. Wat (MC-CIG Career Integration Grants, ref 293535) FPI (BES-2010 -039247) 23