High-Level Policy Dialogue on EU Sanitation Policies and Practices in the 2008 International Year of Sanitation High-level low-cost sanitation services in small towns and large villages Duncan Mara University of Leeds, UK

The Options: On-site sanitation (e.g., pour-flush toilets + leach pits)On-site sanitation (e.g., pour-flush toilets + leach pits) Low-volume flush toilets + simplified sewerage + low-cost wastewater treatment (e.g., waste stabilization ponds)Low-volume flush toilets + simplified sewerage + low-cost wastewater treatment (e.g., waste stabilization ponds)

Low-volume flush toilet For example, Swedish models that use 3 litres per flush:

Simplified sewerage Rigorous hydraulic design based on: a minimum sewer diameter of 100 mm a minimum tractive tension of 1 N/m 2 a minimum value for peak wastewater flow of 1.5 litre/second This results in a minimum gradient of 1 in 200, and a 100 mm dia. sewer being able to serve 234 households of 5 people with a water consumption of 100 litres/ person day. This results in a minimum gradient of 1 in 200, and a 100 mm dia. sewer being able to serve 234 households of 5 people with a water consumption of 100 litres/ person day.

Comparative costs (1997 US$) of conventional and condominial sewerage in Parauapebas, Pará, north Brazil Item Conventional sewerage Condominial sewerage Total cost Cost per connection Total cost Cost per connection Excavation263, ,00028 Inspection chambers 181, ,00013 Sewers185, ,00015 Total629, ,00056 Source: Melo (2005).

Brasília Simplified sewerage in rich areas as well as in poor areas

CAESB, the water & sewerage company for Brasília and the Federal District, basically asked itself: Answer: Yes. If condominial sewerage works well in poor areas, shouldnt it also work well in non-poor areas? Answer: Yes. The next question is: As condominial sewerage works well in both poor and non-poor areas, should we ever use conventional sewerage in urban housing areas?Answer: NO. As condominial sewerage works well in both poor and non-poor areas, should we ever use conventional sewerage in urban housing areas? Answer: NO.

Waste stabilization ponds Widely used in France (>2500 systems) and Germany (>3000)Widely used in France (>2500 systems) and Germany (>3000) France: Facultative pond (6 m 2 /p.e) + two maturation ponds (each 2.5 m 2 /p.e)France: Facultative pond (6 m 2 /p.e) + two maturation ponds (each 2.5 m 2 /p.e) Research in UK: Facultative pond (as in France) + aerated rock filter (1 m 2 /p.e) produces a very high quality effluentResearch in UK: Facultative pond (as in France) + aerated rock filter (1 m 2 /p.e) produces a very high quality effluent

Facultative and maturation ponds are GREEN because of the ALGAE that grow in them

Algalbacterial mutualism Algae Bacteria O2O2 CO 2 New cells Light Wastewater BOD

Québec No! Too cold for WSP in Europe? No!

Chappelle Thouaroult, Brittany, France

Capital and O&M costs of various wastewater treatment processes for 1000 p.e. in France in 1998 Treatment Capital costs O&M costs process ( p.e. –1 ) ( p.e. –1 a – 1 ) Activated sludge Trickling filter RBC Aerated lagoon Settler-digester + CW WSP

1. Anaerobic pond Small WSP system in Bavaria Village of Berg, near Munich (pop. ~250) Mean temp. of coldest month (Jan.): 2°C

2. Secondary facultative pond

Capital and O&M costs of various wastewater treatment processes for 500 p.e. in Germany in 1996 Treatment Capital costs O&M costs process (DM p.e. –1 ) (DM m –3 ) Activated sludge 2, Trickling filter 1, Aerated lagoon 1, Vertical-flow CW 1, Horizontal-flow CW 1, WSP Average 1996 exchange rate: DM1 = 0.53

PERTHSHIREPERTHSHIRE SCOTLANDSCOTLAND Loch Achray Tigh Mor Trossachs WSP

The effluent from a facultative pond loaded at 80 kg BOD/ha d complies with the UWWTD

(91/271/EEC)

Rock filter receiving maturation pond effluent – Veneta, Oregon Fac. pond Mat. pond Rock filter Baffle

Suspended solids removal

Summer Results for effluent ammonia-N/l: Aerated RF: <2 mg/l Unaerated RF: ~7 mg/l Planted bed: ~4 mg/l BUT Winter Results for effluent ammonia-N/l: Aerated RF: <2 mg/l Unaerated RF: ~8 mg/l Planted bed: ~7 mg/l

Natural vs Conventional Wastewater Treatment Basically a choice between LAND and ELECTRICITY: Basically a choice between LAND and ELECTRICITY: Money spent on land is an investmentMoney spent on land is an investment Money spent on electricity is money gone for everMoney spent on electricity is money gone for ever