SEWAGE SYSTEM SOLUTIONS Current Issues in Ontario & Case Studies of Innovative Approaches to Remedy Failing Systems

Transcription

1 SEWAGE SYSTEM SOLUTIONS Current Issues in Ontario & Case Studies of Innovative Approaches to Remedy Failing Systems Marie-Christine Bélanger Director Ontario Onsite Wastewater Association Rick Esselment Vice-President Ontario Onsite Wastewater Association October 7th 2013 Hamilton, Ontario

2 Content Introduction Onsite sewage treatment Some statistics Problems encountered in the field Solutions Other jurisdiction Case studies

3 Introduction The idea of this presentation came after a tour of MMHA and MOE in the province of Qc to meet Qc MOE and the BNQ relative to the adoption of the CAN/BNQ in the OBC Part 8.

4 To protect and promote the benefits and value of onsite and decentralized wastewater management through education, improved standards of practice and advocacy for sound policies across the province

5 Onsite Sewage Disposal Systems?

6 Onsite Wastewater Treatment Systems

7 Some Statistics Ref: USEPA

8 Some Statistics Ref: USEPA 55% of failures are related to poor maintenance Conventional systems are not permanent infrastructures, but technologies can be!

9 It is time for a change of context

10 We have an opportunity to do better

11 Distribution Boxes

12 If something doesn t seem quite right it usually isn t, so keep looking

13 What are we waiting for?

14 What are we waiting for?

15 Case Study 3 bedroom 2200 sq ft home 50 year old septic system

16 Challenge No signs of bed failure 6 m from house to property line Leaching field in this area OBC requires 5 m to dwelling and 3 m to property line

17 Case Study 3 bedroom 1100 sq ft home 50 year old septic system

18 Case Study Outside of tank no connection to leaching field Septic tank has failed

19 Challenge Leaching field is failed 10 m from house to property line Leaching field in this area No room for leaching field or mantle

20 Case Study 3 bedroom 1100 sq ft home 50 year old septic system

21 Case Study Heavy clay soil Failed leaching field Field envelope is 70 m²

22 Possible solutions under the current OBC Holding tanks Compliance alternatives (OBC 11.5) Same system w/o compliance with horizontal setbacks Treatment unit with a reduced vertical clearance and smaller footprint (area bed and shallow buried trenches)

23 What should we be seeking? Offering value-added solutions designed to perform and last Protecting shared water resources Ensuring a cleaner environment for communities and families

24 Case Studies from different jurisdictions Cluster installation (St-Joseph-de-Kamouraska) Small lots and sensitive zone (Lac-Beauport)

25 Case Study #1 St-Joseph-de-Kamouraska Alternative to Conventional Sewer and Decentralized WWT Cluster Installation

26 Case Study #1 St-Joseph-de-Kamouraska Municipality Rural municipality in the Lower St-Lawrence region Population: 428 Territory: 86,5 km² Density: 5,1 inhabitants/km2

27 Context 80 residences and businesses (260 inhabitants serviced) Daily flow: 76 m3 Contaminated individual drinking water wells (too small lots, failing septic installations) Shallow bedrock and floodplain Limited available space near the urbanized perimeter to implement a conventional approach

28 Rivère-du-Loup river Cost of a conventional solution consisting of aerated lagoons connected to the municipal sewer system? 2 M$ St-Joseph-de-Kamouraska

29 Solution Advanced treatment Biofilter technology with effluent discharge into the Rivière-du-Loup river 15 mg/l in TSS and in BOD CFU/100 ml in FC Complete installation 1 septic tank with effluent filter per residence small diameter collection system (2,500 linear meters) 5 treatment sites spread out in the municipality for a total of 80 Biofilter units ( the costs of the collection system)

30 Rivère-du-Loup river St-Joseph-de-Kamouraska

31 Project Executed in the summer of 2001 Cost: $950,000 Collection work: $600,000 Treatment: $350,000 (septic tanks and Ecoflos) Grant: Quebec s Programme des eaux vives Non-subsidized portion assumed by the municipality via a 20-year loan Costs to citizens: $373/year Site #1 (30 biofilters 3 clusters of 10 units)

32 Operations Operational cost: $300/residence per year (including filtering media replacement) Low energy: 450 kwh/month ($30-35/month) No intervention needed on the network No water infiltration

33 Performance True average flow: 53 m3/d 70% of the design Q Treatment Performances (2002 to 2012) Parameters Influent Summer effluent (T > 7oC) Winter effluent (T < 7oC) Discharge criteria MES (mg/l) 47 ± 12 5±3 3±2 15 DBOC5 (mg/l) 157 ± 42 3±2 5±2 15 NH4 (mg/l) 39 ± 6 2,6 ± 2,5 5,7 ± 1,7 -- CF (UFC/100 ml) n s. o.

34 Case Study #2 Lac-Beauport Highly Treated Effluent to Allow Direct Surface Discharge

35 Case Study #2 Lac-Beauport Regional municipality located 20 kilometers from downtown Quebec City Population: 6145 Territory: 64 km² Density: 98 habitants/km2

36 Context Currently 9 high-value properties, some lakefront, with failing conventional septic systems Runoff waters to Beauport Lake No possibility of installing a new leaching field on any of the properties (small lots and shallow rock) only option was holding tanks Limited space between residences Older residences with extensive existing landscaping

37 Context Quebec regulation only allows holding tanks as a last recourse Municipality desperate for a different solution concerned about impact of holding tanks on property value and the complexity of their maintenance Quebec regulation allows for direct discharge for septic system conditional to disinfection and/or P removal depending on the sensitivity of the receiving environment Project started in the Fall of 2012

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39 Solution Phosphorus Removal Unit with direct surface discharge to ditch ending in Beauport Lake <10 mg/l in TSS and in BOD5 <0.3 mg/l P <200 CFU/100 ml in FC Complete installation per residence 1 primary reactor + 1 DpEC Unit + Biofilter + DiUV Bypassed the existing disposal field Modularity allowed for greater flexibility regarding distances to respect

40 System Installed Ptot: 0,1 mg/l Ptot: 0,4 mg/l Tertiary treatment level BIV, DII, PII Ptot: 0,1 mg/l

41 Average Performance

42 Other possible configurations

43 System costs Cost for phosphorus removal unit: $8,995 (Primary reactor and EC unit) Excavation work: Average of $10,000 Complete treatment chain: $15,000 (including Biofilter, phosphorus removal unit and all systems components)

44 System installed Light system requiring regular machinery Single-day installation for each treatment plant

45 Remediation Costs Holding Tank Average cost of septic tank: $3,000 Average cost of excavation work: $2,500 Average cost of pump-outs: $500 to 800 per pump out/month (to treatment plant) Holding tank should be a last resource and temporary solution not a long-term sustainable solution

46 Operation & Maintenance Costs Electricity and replacement of the aluminum plates 20$ / month 12$ / month <10$ / month

47 Conclusion Highlight of existing problems and applicable solutions Need to start talking about how to bring them (problems and solutions) together Come to OOWA conference to continue the discussion on how to implement these solutions

48 Thank you! Questions?

49 Summary of CAN/BNQ Standard Treatment Classes Basic level (B)* Treatment classes TSS CBOD5 B-I B-II B-III B-IV * In mg/l Treatment classes Disinfection (D) UFC/100 ml Phosphore (P) mg/l Nitrogen (N) FC ou E. Coli* P total N total D-I D-II 200 D-III ND (median < 10) P-I 1,0 P-II 0,3 N-I 50% N-II 75%