Auditing Water Resources for Application
to Water-Sensitive Urban Design:
A Case Study in the Lima (Perú)
Metropolitan Area
Kara Jean McElhinney, M.Sc.
Young Researchers’ Forum, BMBF “Future Megacities in Action” Conference
May 13, 2013
Advisement:
Prof. Dr.-Ing. Heidrun Steinmetz & Dipl.-Ing. RBM Carsten Meyer
Institut für Siedlungswasserbau, Wassergüte- und Abfallwirtschaft, Uni Stuttgart
Prof. Dipl.-Ing. Antje Stokman & Dipl.-Ing. Eva Nemcova
Institut für Landschaftsplanung und Ökologie, Uni Stuttgart
Challenges in Lima
2
Challenges in Lima
Natural stressors:
• arid climate
•poor distribution of surface
water resources
• topography
“Man-made” stressors:
• fast, informal, low-density
population growth
• effects of climate change
…create consequences for:
• potable water supply and distribution
• wastewater collection and removal
• providing and maintaining urban green space
3
Sustainable & Integrated
Urban Water Management
Water-Sensitive Urban Design
• manage water resources
sustainably
• protect aquatic ecosystems
• integrate management of
total water cycle into urban
design and built form
• enhance landscape towards
creation of an urban ecology
A water audit can guide and constrain WSUD by
providing information about the quantity and
quality of available water resources
4
Thesis Framework & Goals
TECHNICAL
DESIGN
PHASE I: INITIAL
IMPRESSIONS
STRATEGIC
PLANNING
PHASE II: “LIMA:
BEYOND THE PARK”
SUMMER SCHOOL
PHASE III:
ANTEPROYECTO
SUMMER
SCHOOL DESIGN
IDEAS
ANTEPROYECTO
DESIGN
IDEAS
INFORMATION
&
IDEAS
INFORMATION
&
IDEAS
OBSERVATION, WATER
INTERVIEWS,
SITE
AUDIT
PRELIMINARY
RESEARCH DEVELOPMENT FIELD TESTING
FINAL
DELIVERABLES:
RECOMMENDED CW
TECHNOLOGIES,
LAND AREA
ESTIMATIONS
DIMENSIONING TOOL
DEVELOPMENT, CW
LABORATORY
TECHNOLOGY
TESTING, FINAL
RESEARCH
AUDIT RESULTS
5
Thesis Framework & Goals
TECHNICAL
DESIGN
PHASE I: INITIAL
IMPRESSIONS
STRATEGIC
PLANNING
PHASE II: “LIMA:
BEYOND THE PARK”
SUMMER SCHOOL
PHASE III:
ANTEPROYECTO
SUMMER
SCHOOL DESIGN
IDEAS
ANTEPROYECTO
DESIGN
IDEAS
INFORMATION
&
IDEAS
INFORMATION
&
IDEAS
OBSERVATION, WATER
INTERVIEWS,
SITE
AUDIT
PRELIMINARY
RESEARCH DEVELOPMENT FIELD TESTING
FINAL
DELIVERABLES:
RECOMMENDED CW
TECHNOLOGIES,
LAND AREA
ESTIMATIONS
DIMENSIONING TOOL
DEVELOPMENT, CW
LABORATORY
TECHNOLOGY
TESTING, FINAL
RESEARCH
AUDIT RESULTS
6
Thesis Framework & Goals
TECHNICAL
DESIGN
PHASE I: INITIAL
IMPRESSIONS
STRATEGIC
PLANNING
PHASE II: “LIMA:
BEYOND THE PARK”
SUMMER SCHOOL
PHASE III:
ANTEPROYECTO
SUMMER
SCHOOL DESIGN
IDEAS
ANTEPROYECTO
DESIGN
IDEAS
INFORMATION
&
IDEAS
INFORMATION
&
IDEAS
OBSERVATION, WATER
INTERVIEWS,
SITE
AUDIT
PRELIMINARY
RESEARCH DEVELOPMENT FIELD TESTING
FINAL
DELIVERABLES:
RECOMMENDED CW
TECHNOLOGIES,
LAND AREA
ESTIMATIONS
DIMENSIONING TOOL
DEVELOPMENT, CW
LABORATORY
TECHNOLOGY
TESTING, FINAL
RESEARCH
AUDIT RESULTS
7
Thesis Framework & Goals
TECHNICAL
DESIGN
PHASE I: INITIAL
IMPRESSIONS
STRATEGIC
PLANNING
PHASE II: “LIMA:
BEYOND THE PARK”
SUMMER SCHOOL
PHASE III:
ANTEPROYECTO
SUMMER
SCHOOL DESIGN
IDEAS
ANTEPROYECTO
DESIGN
IDEAS
INFORMATION
&
IDEAS
INFORMATION
&
IDEAS
OBSERVATION, WATER
INTERVIEWS,
SITE
AUDIT
PRELIMINARY
RESEARCH DEVELOPMENT FIELD TESTING
FINAL
DELIVERABLES:
RECOMMENDED CW
TECHNOLOGIES,
LAND AREA
ESTIMATIONS
DIMENSIONING TOOL
DEVELOPMENT, CW
LABORATORY
TECHNOLOGY
TESTING, FINAL
RESEARCH
AUDIT RESULTS
8
Water Resources in Chuquitanta
9
Water Resources in Chuquitanta
10
Water Resources in Chuquitanta
11
Audit Development:
Choice of Parameters
Water Quantity
12
Audit Development:
Choice of Parameters
Water Quantity
Nutrient Content
Other
Temperature
Oxygen Balance
Microbiology
Salt Content
Acidity
13
Audit Development:
Choice of Parameters
1. Which water quality parameters are typically considered in the
assessment of surface waters and wastewaters in Germany and in
Perú?
14
Audit Development:
Choice of Parameters
1. Which water quality parameters are typically considered in the
assessment of surface waters and wastewaters in Germany and in
Perú?
2. Which parameter levels might be affected by “upstream”
activities, or by day-to-day uses of local water resources?
15
Audit Development:
Choice of Parameters
1. Which water quality parameters are typically considered in the
assessment of surface waters and wastewaters in Germany and in
Perú?
2. Which parameter levels might be affected by “upstream”
activities, or by day-to-day uses of local water resources?
3. Which parameter levels are important to the intended or
“downstream” uses of local water resources?
16
Audit Development:
Choice of Parameters
1. Which water quality parameters are typically considered in the
assessment of surface waters and wastewaters in Germany and in
Perú?
2. Which parameter levels might be affected by “upstream”
activities, or by day-to-day uses of local water resources?
3. Which parameter levels are important to the intended or
“downstream” uses of local water resources?
4. Which parameters are easiest and cheapest to obtain information
about?
17
Audit Development:
Choice of Parameters
Water Quantity
Temperature
Oxygen Balance
BOD5
COD
DO
Salt Content
EC
ClAcidity
pH
Nutrient Content
Other
NO3-N
NH4-N
Cd
Cr
TKN
PO4-P
Cu
Fe
Ptot
Mn Pb
Microbiology
Zn
TSS
fecal coliforms
fats & oils
heat-resistant coliforms
total coliforms
E. coli
salmonella
helminth eggs
18
Audit Development: Choice of Methods
Send field
samples to private
laboratory for analysis
Least
Desirable
Test field samples
on-site or in-house at
UNI-CITRAR laboratory
Make estimations based on
literature values and data we
already have
Collect data via observation and interviews, and
from available literature and other accessible
sources
Most
Desirable
19
Audit Development:
Choice of Methods
Water Quantity
Temperature
Oxygen Balance
BOD5
COD
DO
Salt Content
EC
ClAcidity
pH
Nutrient Content
Other
NO3-N
NH4-N
Cd
Cr
TKN
PO4-P
Cu
Fe
Ptot
Mn Pb
Microbiology
Zn
TSS
fecal coliforms
fats & oils
heat-resistant coliforms
total coliforms
measured using probes
E. coli
measured using Cell Tests
salmonella
evaluated by private lab
helminth eggs
20
21
temperature
pH
EC
DO
COD, NO3-N, NH4-N, PO4-P, Ptot, Cl-
BOD5, total coliforms,
helminth eggs
22
Wetland Area Estimation Tool
Co: target outflow concentration of
dimensioning parameter
Kadlec’s p-k-C* Model
(𝐶𝑜 − 𝐶 ∗ )
=
𝑖
∗
(𝐶 − 𝐶 )
Ci: inflow concentration of
dimensioning parameter
1
𝑘𝐴
1+
𝑃𝑄𝑖
𝑃
C*: background concentration of
dimensioning parameter
k: modified first-order areal constant
A: required wetland area
P: number of tanks in series
Qi: inflow rate
23
Results
Results
exceeds standard
within the limit of standard
no standard available
for comparison
NV no value determined
Domestic Wastewater:
Santa Cruz Hill Residential Area
The Basics
• no connection to water
supply/sewerage network –
potable water delivered by truck
• no formal sanitation facilities
• domestic wastewater discarded
in the street
• high degree of community
engagement and self-organization
26
Domestic Wastewater:
Santa Cruz Hill Residential Area
Main Design Ideas
• collect combined grey- and blackwater
from settlement; carry by gravity to base
of hill for treatment in constructed
wetland
• intended as temporary system until
formal sewerage connections are
installed in Santa Cruz
27
Domestic Wastewater:
Santa Cruz Hill Residential Area
Estimated Wetland Area: 50 m2
28
Domestic Wastewater:
Santa Cruz Hill Residential Area
Recycled vertical flow CW for
greywater treatment: Space saver.
High success with GW treatment.
Requires pump.
UDDTs for collection of urine and faeces:
Potential for reuse in tree fertilization and
improvement of soil.
29
WWTP Effluent:
SEDAPAL Puente Piedra
The Basics
• CSBR-3 built in 2002 to treat
36,460 m3 wastewater per day
(422 L/s) for reuse in irrigation
• higher inflow volumes and
organic loads than anticipated
have caused major operational
problems
• low-quality outflow
nonetheless used for local
agricultural irrigation
30
WWTP Effluent:
SEDAPAL Puente Piedra
Main Design Ideas
• expand wastewater treatment via a lowcost biological treatment system for
secondary treatment of effluent
(envisioned as incorporating ponds or
lagoons)
• include recreational green space
adjacent to treatment ponds/lagoons
31
WWTP Effluent:
SEDAPAL Puente Piedra
Estimated Wetland Area: 8.5 ha
32
WWTP Effluent:
SEDAPAL Puente Piedra
Subsurface CW for wastewater treatment: High reduction in organic content &
pathogens. Requires less space than free surface CW. Minimizes odor problems. Planted
vegetation would increase green area. No problems with TSS since levels in WWTP
33
effluent are low. Good interim choice until plant can be upgraded.
Irrigation Water:
Chuquitanta Canal Network
The Basics
• canal network fed by upstream point
along Chillón River and used for local
agricultural irrigation
• flow rates vary between upstream dry
and rainy seasons, but never fall to 0
• sections of network which pass
through residential areas have been
closed off; others are used as solid
waste and wastewater dumps
34
Irrigation Water:
Chuquitanta Canal Network
Main Design Ideas
• use natural material (i.e., not concrete)
to construct canals, and cover them
where water quality remains poor
• develop canal-side recreation areas
• treat canal water AND household DWW
in canal-side constructed wetlands
• use treated water for irrigation of urban
agriculture and medians/green strips
along avenues
35
Irrigation Water:
Chuquitanta Canal Network
Estimated Wetland Area: 1 ha
36
Irrigation Water:
Chuquitanta Canal Network
Free surface CW for surface water treatment: High reduction in organic content,
nitrate, and pathogens. Water quality good enough for treatment area to double as
green park. Treated water can be re-channelized for use in agricultural or green space
37
irrigation. Requires large land area.
River Water: Chillón River
The Basics
• annual flood and no-flow periods
• dike between settlement and river, but banks not reinforced
• wide variety of pollution sources contribute to low water quality
38
River Water: Chillón River
Low-Water
Mid-Water
High-Water
Main Design Ideas
• river re-naturation incorporating natural morphology and native bank
plantings
• reinforce banks for flood protection
• supplement river flow during dry periods with puquio water and treated
WWTP effluent
39
River Water: Chillón River
Estimated Wetland Area: 39 ha
40
River Water: Chillón River
Terraced CW “modules” for
greywater treatment and river flood
protection
Step 1: Pre-treatment (removal of
oils/fats, gravel/sand filtration) at
central greywater collection point on
the top of dike
Concrete basin with plantings as
CW “module”
Step 2: Water is routed into system of
concrete basins which are planted
with Phragmites australis and
arranged to form riverbank terraces
on the river side of the dike
41
River Water: Chillón River
Terraced CW “modules” for greywater
treatment and river flood protection:
Success in the use of Phragmites
australis in nitrate removal AND in
riverbank stabilization by vegetation.
Concrete basins and will provide
additional bank stability. Basin plantings
will serve to green riverbank. Requires
pump or manually carrying water from
settlement to top of dike. One part of a
more comprehensive solution needed
for river.
Tawantinsuyu agricultural terracing
in the southern Peruvian Andes
42
Summary of Results & Recommendations
Domestic WW
AUDIT
RESULTS
BOD5, NO3-N,
Ptot, fecal clfms.,
Salmonella,
helminth eggs,
TSS, TKN,
quantity
WWTP Effluent
Irrigation Water
BOD5, COD, PO4P, Ptot, Cl-, ,
thermotol.
clfms., total
clfms., helminth
eggs, DO, NO3-N,
NH4-N, TSS,
temp., pH, EC,
quantity
NO3-N, Cd, Cu, Fe,
Mn, Pb, fats/oils,
COD, NO3-N,
thermotol. clfms.,
total clfms.,
BOD5, DO, NH4- total clfms., E. coli,
BOD5, COD, DO,
N, PO4-P, Ptot, Cl-,
NH4-N, PO4-P, Ptot,
helminth eggs,
Cl-, temp., pH, EC,
temp., pH, EC,
Cr, Zn, helminth
quantity
eggs, quantity
River Water
DESIGN
RESULTS
FINAL REC.
recycled vertical
flow CW & UDDT
subsurface CW
free surface CW
terraced CW
“modules”
43
Thank You! Any Questions?
44