210,000,000 gallons of water distributed daily by Denver Water 140,000,000 gallons of wastewater treated daily by Metro Wastewater Reclamation District 350 gallons of water used daily by a single family home
down on energy use in wastewater treatment processes. By switching from the conventional anaerobic process to a composting system, thousands of dollars can be saved every year. Not only does composting reduce energy use and costs, but composted biosolids are productive in a variety of ways. Composting facilities help to reduce greenhouse gas emissions that are produced during the anaerobic digestion process. Commonly, composted biosolids can be applied to agricultural land to restore eroded soils and degraded crops, yet compost can be used to
Composting sludge is one of the most productive ways to cut on
primary clarifier
aeration basins
Energy Use
fer tilize household lawns, remediate brownfields, restore wetland habitats, and cap landfills.
29 kWh daily
Conventional Sludge Treatment Process
24189 kWh daily
834 homes
secondary wastewater process
average home consumption
KrapPARK is a project that proposes a system of composting facilities to create a more energy efficient wastewater treatment process. The compost web follows sludge from the beginning until final distribution to productive uses focusing in the Boulder, CO area. The network is easily replicable and can be linked to other wastewater facilities creating an energy efficient and productive landscape.
wastewater grit basin
productive uses of wastewater sludge Denver’s wastewater reclamation facility processes up to 140 million gallons of water daily, resulting in the production of 68 dry tons of sludge. The current sludge processing procedure, anaerobic digestion, of biosolids at the Denver facility requires large amounts of energy resulting in annual production costs of over a million dollars. With increasing population in the South Platte River Basin, energy use at wastewater facilities is expected to increase.
Wastewater Treatment Cycle
Goals & Objectives
chlorination/dechlorination river water
Utilize productive uses for composted sludge -Agricultural Application -Brownfield Reclamation -Landfill Capping -Wetland Restoration -Residential application
Reduce energy requirements through alternative sludge processing Reduce greenhouse emissions and landfill disposal of sludge and biosolids Reduce imports of biosolids to the South Platte River Basin
biosolid fertilizer
Engage community through interactive green waste sorting and composting processes
secondary clarifier
anearobic digestion
Benefits of Sludge Composting As Compared to Conventional Anaerobic Digestion Processes
Proposed Sludge Treatment Process Proposed Process
Aerated Pile Composting 18.3 kWh per dry ton
Current Process
Anaerobic Digestion 560 kWh per dry ton
Fo
68.50 38,360 $3,038.80 $1,120,112.00
rt C ol
68.50 1,253.55 $100.28 $36,602.00
dry tons daily daily kWh daily expenses yearly expenses
0.5% reclamation 1.5% rangeland
57%land application
river water
7% transfer
biosolid soil
8% stored
dry tons daily daily kWh daily expenses yearly expenses
wetland dechlorination
9% clarifier dewatering landfill
lin
B
s
ou
17% composting
ld er
Savings
N G
37,106 kWh daily electrical savings $2,938.52 daily monetary savings $1,072,370.00 yearly monetary savings
biosolid composting pile
biosolid fertilizer
Colorado Biosolid Use: 2007
re el
Sludge Processing
ey
2007 Biosolid Use in Colorado
D
Sludge Importing
en ve r
Colorado produces about 99,000 dry tons of sludge annually.
Colorado impor ts about 34,000 dry tons of sludge annually.
0.5% reclamation 1.5% rangeland
57%land application
7% transfer 8% stored
After processing, Colorado uses about 102,000 dry tons of sludge beneficially
9% landfill
each year.
17% composting
Colorado imports about 34,000 dry tons of sludge annually.
After processing, Colorado uses about 102,000 dry tons of sludge beneficially each year.
Soil Water Capacities
Crop Nitrogen Requirements
For t Collins
Composting Web
parameters
Transportation Network
Colorado Biosolid Use: 2007
Composting Web Colorado produces about 99,000 dry tons of sludge annually.
Greeley
Colorado imports about 34,000 dry tons of sludge annually.
After processing, Colorado uses about 102,000 dry tons of sludge beneficially each year.
At a regional scale, the project consists of a rhizomatous web of linkages between existing wastewater treatment facilities and proposed composting facilities. The composting facilities are strategically placed near transportation infrastructure and agricultural lands, as well as centralized among existing wastewater treatment facilities state-wide. The composting nodes facilitate the collection, distribution, and productive uses of wastewater byproducts for both public and private entities.
N
N
N
N
Boulder
Denver
Sludge
Sludge refers to the residual solid or semisolid material separated from wastewater during wastewater treatment processes.
TOILET
Biosolids
Composted Biosolids
Biosolids are treated sewage sludge that meets the EPA pollutant and pathogen requirements for land application and surface disposal.
0.00-0.02 0.03-0.09 0.10-0.14 0.15-0.17 0.18-0.20
Highways
Composted biosolids are organically rich soils that contain a well-balanced array of micronutirents that are capable of conditioning degraded soils through land application.
Railroads Composting facilities are located nearby transpor tation infrastructure to ensure efficiency and convenience in the collection of wastewater byproducts and the distribution of composted biosolids throughout Colorado.
WASTEWATER FACILITY
SEWER
Waldon Ponds Wildlife Habitat
Compost Distribution Center
Facility on site, as well as green waste delivered by the public. The mixture is composted and conver ted into nutrient rich soil that is later sold for use by both public and private entities. KrapPARK is a
W
Public Delivery Trucks Composting Equipment
W
Air Circulation from Blower unique facility because it involves members of the community which facilitates sustainable solutions for waste disposal and productive uses for wastewater byproducts.
Raw Compost Mixture
LANDFILL CAPPING::composted sludge Perforated Pipe
Raw Sludge Mix Curing of Compost Final Composted Biosolids
restoring landfills with municipal wastewater N Aerated byproducts Static Pile
Waldon Ponds Wildlife Habitat
opportunities for public open space
2000
a c r e s
powers 10 lightbulbs for 712 hours
Fresh Kills Park Staten Island, New Jersey
a c r e s Hiriya Park Tel Aviv, Isreal
1100
uncovered full landfill
BAGE
GAR
a c r e s Hassell Millenium Parklands Sydney, Australia
landfill capped with composted soils
BAGE
GAR
synfuel pipeline quality
environmental impacts
heating
GREENHOUSE EMISSIONS ONE acre of capping methane emissions
electricity
methane uses
= planting 11,667 acres of trees or
Landfill Capping K Mg Na S
Composted biosolids are an effective method of remediating toxic soils contaminated by industrial pollution because they:
Al
Mg S Al Fe K Na
P
Fe P,N Ca
- Increase soil fer tility
N H Ca
- Correct soil pH levels
- Improve physical proper ties of soil
Oxygen
Si
Si Carbon
C
Average Soil
Rachel Barth & Kylie Harper
|
Wetland Restoration
Composted biosolids have the most suitable structure for landfill capping projects.
Oxygen
capped landfill
Composted Biosolids
8,334
methane collection
- The soil structure allows for appropriate root penetration to help prevent leachate problems
composted soils
landfill gas contains 50% methane - Composted soils have the richest amount of nitrogen other nutrients to provide optimal growing and 50% CO2 andallowing energy conditions collection and production
- Capping with compost in evapotranspiration caps allows for the waste and garbage to decompose below the surface
LAR 648 Mile High Water: Design Strategies for Denver’s Drylands
foundation
garbage Evapotranspiration Cap
|
Professor Canfield
Polishing Wetland
Composted biosolids can be used in the production removing cars from of floating wetland islands that are used to restore wetlands. or
evapotranspiration
Brownfield Reclamation
the road composted biosolids
- Islands act as a water purifier, collecting toxins from the polluted wetland - Wildlife habitats are restored through the addition of floating islands
microbes (biofilm)
treated wastewater
south platte river
benthic layer
preventing the use of 101,331 barrels of oilBiosolid Island Composted
|
Kansas State University
|
Fall 2011
productive uses
Denver Regional Landfill
2200
15 2 1 s k e e W
Composting Cycle
Aerated Blower
1 acre of capped landfill = 712 kWh daily
7 4 s eek
1 1 8 s k e e W
Finished Compost
Aerated Static Composting Piles
Captain Jack Mine Reclamation Site
3 1 s eek
Sludge Mixing Center
Boulder Composting Network KrapPARK Regional Compost Center is located ten miles east of downtown Boulder and is the first phase of the proposed composting network. KrapPARK mixes sludge from Boulder Wastewater Treatment
PRODUCTIVE USES
Circulation
Recycling Center
Denver Regional Landfill
The proposed composting facilities are also located near existing wastewater treatment plants to facilitate the exchange of wastewater byproducts to be conver ted into useful products by the composting facilities.
design prototype
Government tax breaks for reducing greenhouse gas emissions
Boulder Regional Compost Center
Agricultural crops require varying amounts of nitrogen in their soils. Because additional micronutrients can be added into the biosolid mixture, composted biosolids are an effective method of providing nitrogen to crops. For this reason, the composting facilities are located near agricultural lands.
Composted biosolids go through a cycle of three stages; mixing, composting, and curing. Once the composted biosolids are curated, the soil is ready for sale and distribution. From star t the finish, a single load of sludge takes approximately six weeks to complete the composting cycle.
Create grants to support research at compost facilities
k r aPPark
Proposed Composting Facilities
Composting Center Prototype
Establishing a program that trades compost for public waste
Boulder Wastewater Treatment Facility
High
k r aPPark
Affiliate with Trash Tax in Boulder to support entities transitioning to zero waste
Public Compost Center
Existing Wastewater Treatment Facilities
COMPOST FACILITY
Incentives Captain Jack Mine Reclamation Site
Low
Because the application of composted biosolids to a soil increases the available water capacity, which helps plants survive longer in droughty conditions, the composting facilities are strategically located on or near soils with low available water capacities.
regional network
kraPPark
Metro Wastewater Reclamation District, Denver, CO