Cornell Waste Management Institute Cornell Waste Management Institute Land Application of Sewage Sludges Topics of Current Concern Ellen Z. Harrison, Director Cornell Waste Management Institute Dept. of Crop and Soil Sciences http://cwmi.css.cornell.edu
45
Embed
Cornell Waste Management Institute Land Application of Sewage Sludges Topics of Current Concern Ellen Z. Harrison, Director Cornell Waste Management Institute.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Cornell Waste Management Institute Cornell Waste Management Institute
Land Application of Sewage Sludges
Topics of Current Concern
Ellen Z. Harrison, Director
Cornell Waste Management Institute
Dept. of Crop and Soil Sciences
http://cwmi.css.cornell.edu
Cornell Waste Management Institute Cornell Waste Management Institute
Topics of Current Concern• Excess nutrients (particularly P)• Human health
– Aerosols and odor– Water (wells and runoff)– Direct contact– Food chain (animal products, home garden)
• Long term agricultural productivity/Ecohealth– Phytotoxicity (metals)– Soil health (metals, organic chemicals)
Cornell Waste Management Institute Cornell Waste Management Institute
Health Effects of Land Application
"The NRC report issued in July 2002 concluded that, although there is no documented scientific evidence that the 503 regulations have failed to protect public health, further scientific work is needed to reduce persistent uncertainty about the potential for adverse human health effects from exposure to biosolids.” EPA letter, 2004
Cornell Waste Management Institute Cornell Waste Management Institute
NRC Findings
• Complex mix of toxic chemicals, infectious organisms, and endotoxins may be present
• Anecdotal reports of adverse health reactions
• No “documented scientific evidence” of failure to protect public health
• Lack of exposure and health info on exposed populations
Cornell Waste Management Institute Cornell Waste Management Institute
Absence of Evidence is not
Evidence of Absence
Cornell Waste Management Institute Cornell Waste Management Institute
Stakeholder Involvement
• Called for by NRC• Real contribution to research through
local knowledge• Mutual understanding of limitations of
research
Cornell Waste Management Institute Cornell Waste Management Institute
Location (# Incidents)
People Affected Resp GI Burn
Head/ Flu
Lesion/ Rash Bleed Other
AL (1) 10+ x x x x x x x
AZ (1) 100+ x x x x x x x
CA (5) 147+ x x x x x x x
FL (4) 32+ x x x x x x x
IA (2) 4+ x x
MD (1) 3 x x x x
ME (1) 3 x x x
MO (1) 2 x
NV (1) 3+ x x x x
NC (1) 2 x x x x
NH (3) 22 + x x x x x x x
11/17/04
Cornell Waste Management Institute Cornell Waste Management Institute
Location (# Incidents)
People Affected Resp GI Burn
Head/ Flu
Lesion/ Rash Bleed Other
OH (6) 14+ x x x x x
OR (1) 4 x x x x
PA (6) 20+ x x x x x x
TN (2) 4+ x x
TX (2) 6+ x x x x
VA (4) 43+ x x x x x x x
WA (2) 6 x x x x x x
WV (1) 3 x x x
WI (1) 2 x x x x
Canada (4) 24 x x x x x x xTotal 21 (50) 454 18 15 11 17 13 9 18
11/17/04
Cornell Waste Management Institute Cornell Waste Management Institute
Cornell Waste Management Institute Cornell Waste Management Institute
What about Class A EQ?
No different than Class B EQEndotoxinsNutrientsChemicalsOdor potential Note that processing mode impacts fate and transport, odor potential, pathogens
Cornell Waste Management Institute Cornell Waste Management Institute
Risk assessments contain many assumptions and policy choices
Examination of Several Assumptions that Dramatically Impact Calculated Risks
• Assessing the Risk to Surface Water• Assessing the Risk to Groundwater• Assessing the Risk of Cadmium to Home
Gardener Using Sludge– How much of each crop does the exposed person
eat?– How much Cd uptake into the crops?
Cornell Waste Management Institute Cornell Waste Management Institute
Map of NYS Showing Relative Size of Watershed and Sludge Site Under 503 RA Assumptions
Only 0.24% of watershed assumed to receive sludge.
Watershed: 427,000 ha
Sludged Area: 1074 ha
A small stream may have much greater %of watershed receiving receiving sewage sludges. What is the risk to person fishing such a stream? What is the environmental risk?
Example
Cornell Waste Management Institute Cornell Waste Management Institute
Sludges and Water Quality
• Movement to Groundwater– In solution– Macropore preferential flow– Enhanced/facilitated transport
(movement of contaminant associated with organic matter)
Cornell Waste Management Institute Cornell Waste Management Institute
Groundwater and 503 RA
• Rapid flow phenomena aren’t accounted for in EPA model (macropores)
• One test tube experiment with one sludge and one soil are basis for metal mobilities to groundwater in the EPA risk assessment
• Substantial dilution or attenuation of leachate before reaching receptor well is assumed (arsenic’s leachate/well concentration ratio is 230)
Cornell Waste Management Institute Cornell Waste Management Institute
Example:TCLP Leachability of Metals as % total metals
Sludge Products Behave Differently
Richards, et al 1997
Cornell Waste Management Institute Cornell Waste Management Institute
Preferential Flow Paths
Blue dye reached 6 feet in 1/2 hour
Model would predict ~3 years
Cornell Waste Management Institute Cornell Waste Management Institute
Comparison of Diet Used in EPA Risk Assessment and USDA Recommended Diet
1=EPA daily dietUsed Avg. ~1980 consumptionVeg consumption has increasedHome gardeners eat high veg diet
1+2=USDA Recommended DietAbout 2 x as much veg
How Much Does the Home Gardener Eat?
1 2
Cornell Waste Management Institute Cornell Waste Management Institute
Cadmium Uptake into Leafy Vegetables
4 orders of magnitude difference (Different crops and cultivars, soils, pH, sludges, etc)
Federal 503 risk assessment used geometric mean
Home gardeners eat from a specific, not avg, garden
Uptake value used in 503--------
Cad
miu
m u
ptak
e
Cadmium Loading
Cd uptake into leafy veg, data from field studies
Cornell Waste Management Institute Cornell Waste Management Institute
Allowable Sludge Cadmium (ppm)Allowable Sludge Cadmium (ppm) 120 EPA calc home gardener risk (not the limiting path)
Cornell Waste Management Institute Cornell Waste Management Institute
Use• Nutrient Mgmt plan• Application rate – P based?• Soil testing• Limit annual application amount• Limit cumulative amount• Limit frequency of application• Limit % of a watershed that can be sludged• Not on frozen ground• Not when soils is within 75% of field moisture