FACES

Engineering with an Attitude

Interview with David del Porto

by Andreas Schoenborn, Editor of the EcoEng Newsletter

If you want to comment on David del Porto's words, you can join our discussion list (link at bottom of page).

Contact Sustainable Strategies: http://www.ecological-engineering.com/ss.html

Usually (our clients have) an economic problem resulting from the need to comply with increasingly tightening environmental pollution regulations. They are looking for a solution and are willing to pay for it. What we do with our engineering is: we do the engineering with an "attitude".

In the case of wastewater we believe, that it is an effluent with characteristics and constituents, but its not waste - until it's wasted. We take the utilization approach. We ask: What are the characteristics and constituents of this effluent? What must we do to pretreat them so they can be used by living components and specifically in our case the microorganisms of the soil leading to the uptake of the nutrients and the water by plants.

We (also) go to the beginning. We look at the water use within the household or the building and we attempt to solve the problems (…) where they begin. That envolves first understanding the technology of water conservation and from there, how effluent is created within the home or building. We divide the flows and pretreat or filter them at their sources and then utilize them in planted "wastewater gardens", in and (out) of the building.

We designed a zero discharge system for this home which involved the addition of a greenhouse on the south side of the building. We separated the effluent into black and grey water. We sent the black water - the toilet matter - to a batch composting system. We filtered the grey water first in the kitchen with a grease and particle filter at the washing machine with a 30 micron (= µm) filter for the particles that are non-biodegradable and buoyancy-neutral. We drained that greywater into a sand and gravel planted bed (in a greenhouse) and connected it to a 2000 gallon (=7.57 m3) concrete tank for overflows and for recycle.

The objective (was) then, to plant in this greenhouse phreatophytes - very thirsty plants - and some halophytes that are able to take up sodium. The plants would be able to utilize all of the greywater, as the system matured, and so the tank would have not to be pumped at a cost to the client .

Both local and state regulation authorities approved this plan. My client was able to sell the property with the house and the new buyers are very pleased to have a tropical greenhouse associated with the house that they purchased. They see it as a quality of life improvement at a lower cost of living, because they are getting all of the wonderful benefits of a tropical greenhouse in a cold climate, and they don't have to have the associated cost of the wastewater disposal. That's where the "eco"nomics comes in.

(...) My clients are now seeing this as not only a way of simply solving a problem. The benefit of being associated with living plants on a day- to-day basis affords an added quality of life that is very difficult for most people to understand until they have done that themselves. (..) This environment provides a quality of life at a very low cost of living. And I think, that is going to be the long term success of ecological engineering.

I mean, there are some clients that see this as the right way to go. (For example) we have a new client, a private school that is building a new campus for 150 students and 50 staff on a 70 acres (= 28.3 hectares) campus. They are going to be living on that campus. They are asking us to engineer the systems ecologically with the attached greenhouses from the beginning because of the learning experience. Living that way works for them as a teaching experience. But it also lowers the long term operating expenses, that's the key.

And now comes the question. This is very important, both for ecological and for on-site systems: What most people and the users want is what I call "sewer equivalency". They want to have the wastewater treatment system financed engineered, constructed, operated and maintained by a public authority, but they want the least cost for them.

Today in North America, the centralized treatment plants and collection systems are financed, operated and maintained by the public. (The people) pay user fees often within their taxes, but lately tied to their water bill. If we provide sewer equivalency for property owners who are not on the sewer, that is less costly to both operate, construct and maintain. If the property owners get sewer equivalency, then I think that people will be more willing to accept that.

The people who work for me, for example, have a very diverse background. Some of them are landscape architects. My younger engineers are coming out of school in mechanical engineering, one was actually trained as an aeronautical engineer (...) There isn't yet a school that is producing ecological engineers, the broad based multidisciplined approach.... but it's coming. There are now courses at universities in ecological engineering, and there are individual institutions who are learning more about these types of things (...).

Increasingly the engineering community is realizing that you can get better results for your clients if you use biological and indeed phytological solutions, rather than mechanical, chemical solutions and so the field here in North America is growing.

What's really important is, that ecological engineering today, the way I described it, is a practice that people can make a living at. It's not a theoretical academic pursuit. (..) This is a field where you can join a firm and practice ecological engineering because this type of engineering makes money. We have clients that are paying lots of money to solve their problems. We have a firm and we enjoy a good living, good income, and life is good. I managed to get my 5 children through school, private university, so I think it beats to the fact that this is the right field at the right time.

Bamboo (..) can produce those fibers faster than any of the trees. It is stronger in some of its characteristics than steel or concrete. Also there is a growing demand in North America for bamboo flooring, because it's very beautiful. (..) The cost to import bamboo from China or Jaopan or South America makes bamboo desirable but uneconomical.

However, if you grow the bamboo locally, close coupled with the pig farms that produce the nutrients, you solve the problem of the pig farmer in terms of pollution avoided, and you provide a marketable crop for him to sell. The economics will be the driver of the future, because ecological engineering completes the cycle. It's not simply using natural systems (..) but total utilization as in an ecosystem, because in an ecosystem by definition there is no waste. Everything is used.

What I think that I'm finding is, that when someone has an ecologically engineered system, say, a "garden", if I use that as a metaphor, it changes the way people think. Using the garden metaphor, (makes) people see it as something valuable (...). Probably we only create gardens of things that we see as valuable (...). When they have these ecologically engineered wastewater gardens, they are asking the question : What should I put in my water that's good for my garden? So attitude changes occur (..) along with a technological shift..

Today people are hiring us to design wastewater gardens in the city because the cost of just the water is so high. (..) Because we have combined wastewater treatment with water supply costs, water is now an economic commodity like gasoline. It is not as expensive, but getting there. People are complaining, and the first thing that they do is when they complain, is that they want to use less.

How do these numbers compare to metric units?

One hexa cubic foot (= 1 HCF) equals 2.8 m3. Thus, the price of $5.70 for 1 HCF equals 2 $ per m3. In Newton, the users pay this price for the first 20 HCF (= 56.7 m3). For the next 50 HCF ( = 140 m3) they pay $6.90 per HCF (= 2.43 $ per m3), increasing even more if you use more. These prices are more or less in the range of what we pay in Central Europe (e.g. Switzerland, Germany) for water and wastewater.

However, David del Porto told me that where no sewer and treatment plant is available the costs to pump a sewage holding tank is now averaging $0.15 per gallon (= 39.6$ per m3) and in land over sole-source drinking water aquifer, the cost to pump a holding tank with washwater from a vehicle maintenance facility such as a garage or a carwash is $1.50 per gallon (= 396$ per m3)!

The effort which is necessary to transfer the US units into metric units highlights one of the problems we have in international communication. Another is the question how the Newton water works can be compared to water works in other countries in terms of organizational structure, fee structure, financing structure or even accounting practices.

Andreas Schoenborn