Engineering in Urban
Ecosystems
Perspectives on Engineering using Natural
Systems
Douglas Daley, P.E.
Environmental Resources and Forest
Engineering
SUNY College Environmental Science and
Forestry
Objectives
 Describe
natural resource / ecological
engineering
 Relate cases of integrating natural
processes within urban context
What’s an Engineer?

Engineer :


Design:


a creator, a problem solver, more than applied
science
a creative, intuitive, iterative, innovative,
unpredictable process of developing a solution
Ecological Engineering:

design of sustainable systems that integrate
human society with its natural environment.
Themes

Ecological Engineering and Sustainable
Development share a common philosophy


Use development practices that support a
sustainable world with high quality of life.
Implement engineering practices that protect and
enhance the ability of ecosystems to perpetuate
themselves while continuing to support humanity.
Ecological Engineering
 Harnesses
the self-organizational
properties (complexity, diversity) of natural
systems.
 Adds the element of societal interaction
with existing ecosystems (beyond created
or restored ecosystems) in built
environments.
 Derives benefit from ecosystem.
Principles of Ecological
Engineering

Energy Signature


Self-organization


Eenrgy sources that determine ecosystem structure
Selection processes by which ecosystems emerge
(seed dispersal, animal migration, etc) to determine
species composition, abundance and network
connections
Preadaptation

Fortuitous adaptation by an organism to an entirely
different set of environmental conditions
Engineers Can use Nature in
Urban Environments
 Energy
Management
 Water Quality and Quantity
• Stormwater pollution
 Land

Resource
Abandoned or contaminated sites
• Landfills
• Brownfields

Bioremediation and phytoremediation
Context of a Type II Ecosystem

Energy and
limited
resources
Type 2 systems evolve to
reduce waste generation,
improve energy utilization





Semi-cyclic
Resource limitations exist
Greater efficiency than
Type I
Unsustainable in long term
Increasingly representative
of industrial models in late
20th century
Limited Waste
Project Case Study: Solvay Waste
Beds
 History
Local Industrial Legacy


Soda ash manufacturing
using the Solvay process
(1887 – 1986)
Raw materials locally
available



Solvay Process Company Facility and Erie
Canal, early 1900s
limestone, brine (NaCl) and
water
1907 – Solvay began
operation of settling basins
along Onondaga Lake
Process residues
discharged as a slurry (5%
solids)
Solvay Process Residues



Solvay process to produce
soda ash 1887 -1986
Primarily a non-hazardous
mixture of calcium, magnesium
and sodium compounds
Waste Beds 9 to 15




15 to 21 m deep
270 ha (662 acres)
Elevated chloride levels in
leachate and stormwater
Stressful growing conditions


pH (8.0 – 12.3)
Electrical conductivity
(0.5 – 9.2 dS/m)

Organic matter (0 - 3.9%)
Project Site Location
Syracuse, NY
N 43o 04’ 26” W 076o 14’ 58”
Water Movement in Wastebeds
PPT = (E + T) + RO + DS + D
Provided by Honeywell and O’Brien & Gere
Engineering Issues

Mandate: Protect Public Health and Environment
 Management Choices:



Treat residuals and byproducts (end-of-pipe)
Prevent generation
Existing Problem

Transport mechanisms
• Leachate, erosion (wind and water), contact

Solutions?
• Barriers, diversions, capture and treat
Concept



Develop end use options that substantially
reduce percolation
Develop end use options that result in
environmental and community benefits and
economic development
Integrate engineering, forestry, landscape
architecture to increase public awareness of
environmental quality issues, improve wildlife
habitat, provide recreational opportunity
Proposal

Design and cosntruct an enhanced
evapotranspiration landfill cover system






Reduce percolation into settling basin
Provide biomass resource for energy conversion
Provide wildlife habitat
Restore damaged salt marshes
Add recreational activities
Capture nutrient and carbon resources from biosolids
and woody residuals generated in urban environment
Benefits





Improvement of soil and water quality
• Willow promotes evapotranspiration, which reduces
percolation and minimizes leachate generation and chloride
loading
• Willow is a perennial crop with low erosion potential and the
ability to increase soil C levels
Improvement of biological and landscape diversity
• Bird diversity in willow crops is the same as in natural shrub
lands
Maintenance of productive capacity
• Willow yield has been shown to increase from the first to
second rotation and is maintained in subsequent rotations
Enhancement of regions contribution to global C cycles
• No net addition of CO2 to the atmosphere
Economic development
• Willow has a short supply chain so it is produced and used in
a community, circulating dollars through the local economy
• Enhances momentum in local renewable energy initiatives
Key Design Considerations

Optimizing soil conditions to maximize rooting
depth and soil moisture storage capacity

Site grading and storm water management

Seasonal storage within wetlands and settling
basins

Willow crop rotation and management
procedures
WATER
Engineering Design Criteria
 What






makes a design “good?”
Works all the time
Meets all technical requirements
Meets Code requirements
Requires little or no maintenance
Is safe
Creates no ethical dilemma
Recall “preadaptation”

Salix and Populus the first
woody species to establish
naturally


Tolerant of harsh site
conditions on site (elevated
chloride and pH)
Recall the
Naturally established willow and
poplar on the Solvay waste beds.

Landfill Cover Systems:
Conventional vs.
Evapotranspiration
Reduce percolation
(leachate)



Conventional systems
rely on low
permeability soil and
geomembrane
Alternative systems
enhance
evapotranspiration
Issue: Long-term
reliability, flexibility,
sustainability
Amended waste
material
A conceptual model of the water balance and hydrology of energy
crops (Mirck 2008; Stevens 2001)
Field Performance – Soil
Barriers
 Climate
 Construction
materials and quality
Design: Growth and Yield Field
Trials

Two 2-acre fields (2004)



Multiple Salix varieties
selected from
greenhouse trials (2003)


Two cutting lengths to test
rooting depth and survival
(25 and 50 cm)
High planting density

First-season’s growth of willow on
biosolids-amended Solvay waste (Fall
2004)
biosolids-amended (1986)
unamended Solvay waste
15,000 stems/ha (6,000
stems/ac)
Willow Variety
SX64.
SX61.
SV1.
S365.
9882-34.
9871-31.
9871-26.
9870-23.
9837-77.
98101-66.
SX64
SX61
SV1
S365
9882-34
9871-31
9871-26
9870-23
9837-77
98101-66
Biomass (odt ha-1 3-yr-1)
50
25 cm cuttings
50 cm cuttings
40
30
20
10
0
Today’s view
Simultaneous Heat and Water
(SHAW) Model

Humid climate



30-yr Average Annual PPT
= 978 mm
PET:P = 1.3
Model simulates heat and
water transfer through
soil-plant-air continuum

Management
• Salix as short-rotation
woody crop (SRWC)
• Part 360 Conventional
Cover
(Figure supplied by USDA)
Year 1 New Planting
Percolation & Precipitation (2008)
10.0
0
9.0
5
10
7.0
15
6.0
5.0
20
4.0
25
3.0
30
2.0
35
1.0
0.0
8210
8230
8250
8270
8290
8310
Julian Date yddd (beginning 7/29/08, ending 12/16/08)
8330
40
8350
Precipitation (mm/day)
Average Evacuation (mm/day)
8.0
PLOT A1
PLOT A2
PLOT B1
PLOT B2
Preci pi tatio
n
Year 2 (2009) after coppice
Percolation & Precipitation (2009)
10.0
0
9.0
10
20
7.0
30
6.0
5.0
40
4.0
50
3.0
60
2.0
70
1.0
0.0
9070
9090
9110
9130
9150
9170
9190
9210
9230
Julian Date yddd (beginning 3/11/09, ending 9/27/09)
9250
80
9270
Precipitation (mm/day)
Average Evacuation (mm/day)
8.0
PLOT A1
PLOT A2
PLOT B1
PLOT B2
Preci pi tation
Cumulative Precipitation & Percolation (2008)
400
350
Precipitation & Percolation (mm)
300
250
Cumulative Precip
Perc Plot A1
200
Perc Plot A2
Perc Plot B1
Perc Plot B2
150
100
50
0
8200
8220
8240
8260
8280
8300
Julian Date yddd (beginning 7/29/08, ending 12/16/08)
8320
8340
8360
Cumulative Precipitation & Percolation (2009)
600
500
Precipitation & Percolation (mm)
400
Cumulative Precip
Perc Plot A1
300
Perc Plot A2
Perc Plot B1
Perc Plot B2
200
100
0
9060
9080
9100
9120
9140
9160
9180
9200
9220
Julian Date yddd (beginning 3/11/09, ending 9/27/09)
9240
9260
9280
Material and methods

Total of 18 sensors
used
 Five sensor sizes:
10mm, 16mm,
19mm, 25mm and
35mm
 Hourly sap flow data
collected (g/h)
 Final output: sap
flow liter per day
Time Period Start
Time Period End
SHAW Predicted
Transpiration
Mean Daily
(mm/d)
Total
(mm)
Mean
(mm/d)
Mean
Difference (PM) (mm)
(-) indicates
model under
prediction
Measured Sap Flow
Day
Date
Day
Date
Mean
Total
(mm)
156
5-Jun
178
27-Jun
82.0
3.7
78.9
3.6
-3.1
195
14-Jul
200
19-Jul
19.7
3.9
29.3
5.9
9.6
205
24-Jul
212
31-Jul
31.9
4.6
26.5
3.8
-5.4
237
25-Aug
248
5-Sep
33.8
3.1
5.8
0.5
-28.0
270
27-Sep
281
8-Oct
32.1
2.9
12.3
1.1
-19.8
296
23-Oct
300
27-Oct
3.2
0.8
1.2
0.3
-1.9
Late Season Willow Transpiration
(October-November 2004)
Salix Variety
Sap Flow
(mm/month)
Sap Flow
(l/d/plant)
S25
180
3.4
SV1
65
1.2
SX64
131
2.5
Equivalent
transpiration
350,000 – 968,000
gal/acre/season
Preliminary Model Projections
Deep percolation
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
Mean: 978 mm
SD: 165 mm
Precipitation
No vegetation
19
75
19
77
19
79
19
81
19
83
19
85
19
87
19
89
19
91
19
93
19
95
19
97
19
99
20
01
Water (mm)
Different management regimes
Year
Uniform Stand
3-YR Harvest
Rotation
Deep Percolation (mm)
PPT
No vegetation
CS (0.5m root)
SRC (0.5m root)
Three consecutive years of extreme annual
precipitation coincide with stand establishment
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
Mean Precipitation +/- 1 Standard Deviation
CS maintains constant percolation rate despite
extreme annual precipitation
1975
1978
1981
1984
1987
1990
Year
Percolation increases when harvesting coincides
with greater total annual precipitation
1993
1996
1999
2002
ENERGY
 Biomass
Produced for Energy and
Products


Captured Solar Energy
Renewable
Willow Biomass Production
Select Species
Plant
Grow
Harvest
Coppice
growthcycle.jpg
Potential Uses for Willow Biomass

Bender harvester cuts and
chips willow biomass crops in
one process.
Chips can be used
as a green energy
source for on site
heat and power
generation
 Feedstock to
produce biofuels or
bioproducts
LAND RESOURCE
 Brownfield

site
Abandoned, idle or under-utilized industrial or
commercial facilities where expansion or
redevelopment is complicated by real or
perceived environmental contamination.
 Legacy
of industrial boom/bust cycle
 Artifact of business lending practices,
uncertainty and liability concerns
Multiple Benefits of ET Cover




A. A. Dhondt
Energy independence
CO2 neutral fuel
source for heat and
power generation
Containment and
remediation of soil
and water
contamination
Visually stunning
transformation of a
wasteland into a
green sustainable
industrial site
Creating Spatial Patterns with
Willow
Summary

Ecologically- minded Engineers





Creative
Knowledgeable (science and math)
Interdisciplinary
Communicators (public, regulators, PRPs, scientists,
etc.)
Integration of natural sciences in a “controlled”
environment to address today’s urban
contamination problems and minimize creation
of new problems