A Natural Approach to the Treatment of Effluent

1. A Natural Approach to the Treatment of Effluent

2. What is Effluent ? • Effluent leaving the house encompasses fresh water and organic matter. This can be broken into two categories: • Black water - high solids (bio-solids from toilet, food scraps from kitchen) /Low volume liquids. • Grey water - low solids (hair, lint, body fats, skin) / High volume liquids.

3. It would seem logical that these two flows require two different treatment processes: * Commonly the two flows are connected at the source – this compounds the problem creating a homogenous mix that requires additional treatment.* Surge loads from baths & w/m’s also increase the load on the system’s performance.

4. Common on-site treatment options Primary Treatment • Privy Pit- Compost • Composting System-Heat • Septic Tank- Anaerobic • Vermicomposting- Using worms Secondary Treatment • Home Treatment Plants; • AWTS- Aerobic- Blowers/power 24/7 • Sand Filters • Textile Filters Tertiary Treatment • Chlorination • U/V • Ozone

5. Composting: an aerobic process that uses heat. Advantages Cost effective Converts bio-mass into fertiliser Locatable under the dwelling No water Consumption Disadvantages High maintenance Can Smell Typical Output Range (Leach ate) BOD5 250+ gO/m3 TSS 80+ g/m3

6. Septic Tanks: A process using anaerobic bacteria. • Advantages • Cost effective. • Disadvantages • Putrefies the liquid • Smells • Surge loads carry nutrients • Requires contents to be removed off-site • Requires major earth works to install large tanks • Typical Output Range • (With Outlet Filter) • BOD5 50-250 gO/m3 • TSS 50-150 + g/m3 Airspace Flow Plate Floatable (scum) “Clear Zone” Heavy material sinks (sludge)

7. Package Plants • AWTS- Aerated Water Treatment Systems • Primary Septic Tanks with Sand Filters • Primary Septic Tanks with Textile Filers All the above require; • require external power 24/7. • Maintenance contracts- external dependency for supply • Replacement of wearing parts • Sucker truck- empty primary solids every 3years • Which in-turn is disposed of where?

8. Being responsible for our resources: • There is no such thing as “waste water” • It is our responsibility to restore “used water” to a quality that is safe for the environment. • It is also more sustainable (where possible) to minimise dependency on active systems e.g. electric pumps, suction trucks etc..

9. The challenge is to create a sustainable interface between our current effluent disposal practices and our environment

10. The Solution is Simple: • Look at how natural ecosystems process by-products or effluent…

12. An Ecosystem is a Closed Loop(No “WASTES”) Food Source – animal faeces, carcasses, leaves are all compost ... Worms and micro organisms - feed on compost and convert it into soils. Soil and rock – home for organisms which feed and convert the nutrients and water Plants – also live in the soil which take up water and nutrients used for transpiration and growth Gravity - returns excess water to the sea which in turn evaporates back into the atmosphere completing the hydro-cycle

13. Finished product: A diverse ecosystem of plants, animals, fertile soil, clean water and thus a healthy planet

14. We are part of the ecosystem too… • Each species has a specific role and place within the eco-system: their niche! • If we work with nature… • Nature will work for us. • We can nurture species by maintaining their niche…

15. The AutoFlow System;Primary Treatment for Solids:

16. Vermicomposting: an aerobic process, employing worms and micro-organisms.

17. Advantages:Cost effectiveConverts bio-mass into fertiliserSmall footprint - locatable under the dwellingMinimal odorDisadvantagesSeparate black and grey water flows Typical Output RangeBOD5 4-50 gO/m3TSS 4-50 g/m3

18. Compost Worms will consume at least half their own body weight a day!

19. The Bag System

20. Primary Treatment for liquids…

21. The Grey water filter Advantages Cost effective. Converts bio-mass into fertiliser Locatable under the dwelling Disadvantages ?? Typical Output Range BOD5 4-50 gO/m3 TSS 4-50 g/m3 An aerobic process that screens gross solids and captures soluble material, ie, soap and body fats.

22. Secondary Treatment for Liquids…

23. The Dosing Siphon • The heart of the system • No moving parts • No small orifices to block • Well proven and reliable • When used in conjunction with a media of high surface area the dosing container becomes a…

24. Batch Reactor • During the dose cycle, oxygen is drawn into the media and captured gases are released from the media pores. • Organic material hangs on the surface and is consumed. • Small footprint • Easy to retro fit any system (fall away from the B/R is required)

25. Surface area is the Key • Almost any media is suitable for growing microbes. • The higher the surface area the greater the number of micro-organisms developed. • Mordenite and Zeolites have the greatest surface area.

26. Application to Land • Dosing has now become mandatory throughout most NZ Councils. The Soil Type dictates the approach: • Clay soils require large areas for dispersal. • Sand/free draining areas require a high quality of treatment prior to dispersal. • Evapo-transpiration increases the uptake rate in all situations. • Application is usually applied below ground level via either, a low pressure pipe (LPP) distribution network or RAAM pressure compensating drip irrigation.

27. Low pressure pipe (LPP) is an effective and sustainable way to achieve effective dispersion and minimise local saturation

28. An Evapo-transpiration Field

29. The Vertical Flow Contact Filter (VFCF) Effluent is dosed over a free draining bed of media. The top soil layer is heavily planted which supports the soil dwellers and draws oxygen into the media. Dosing maintains a moist environment, essential for maintaining life. It also distributes the effluent across the entire bed.