Land Application of Sewage Sludges Topics of Current Concern by tfe97690

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									  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
        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)
• Surface water quality
  – Excess nutrients
  – Organic chemicals
  – Metals

                  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
            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
Absence of Evidence
       is not
Evidence of Absence



    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
 Location (#   People                  Head/                   Lesion
  Incidents)   Affected   Resp GI Burn Flu                     / 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

                          Cornell Waste Management Institute
                                                                            11/17/04
Location (#   People                  Head/               Lesion
 Incidents)   Affected   Resp GI Burn Flu                 / 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       x
Total 21
(50)          454          18 15         11       17          13       9       18


                     Cornell Waste Management Institute                11/17/04
        Unevaluated Pathways
     of Concern to Human Health


• Airborne                  • Water borne
  contaminants                contaminants
   – Odors                       – Pathogens
   – Irritants                   – Toxics
   – Pathogens                   – Nitrates
   – Endotoxins
   – Toxics


          Cornell Waste Management Institute
       Examples

• DeSoto, Florida
• Grand Bay, Alabama
• Menifee, California




   Cornell Waste Management Institute
WERF Incident Response Effort


• Biosolids Summit – July 2003
• Public Partnering Protocol
• PSC for Incident Response
  Investigation Project




           Cornell Waste Management Institute
Organic Chemicals in Sewage
          Sludges


•   Many thousand chemicals in use
•   Few studied
•   Limits of detection can be insensitive
•   Lit search obtained data on 516


             Cornell Waste Management Institute
EPA Soil Screening Levels
• Risk-based
• Several exposure paths
• Trigger for site-specific risk
  assessment under Superfund
• Used by NRC as indicator




       Cornell Waste Management Institute
120
          1. Aliphatics
          2. Chlorobenzenes
          3. Flame Retardants
100       4. Monocyclic HC
          5. Nitrosamines
          6. Organotins
          7. PCPs
80        8. Pesticides
          9. Phenols
          10. Phthalate
          11. PCBs
60        12. PAHs
          13. Sterols & Stanols
          14. Surfactants
          15. Phosphate.Esters
40




20




 0
      1       2        3          4     5    6           7          8         9         10   11   12   13   14   15

                                                 # of chem # chem w ith SSLs # chem > SSL


                                      Cornell Waste Management Institute
From NRC, 2002                        A=SSL, ingestion and dermal
                 Cornell Waste Management Institute
      Sludge Application at the Cornell
                 Orchard
• 1978: Ley Creek Treatment Plant (Syracuse,
  NY) sewage sludge, applied at 244
  tons/hectare, till depth 20 cm, 0.08 ratio of
  sludge:soil
• 1979 to 1983: test crops grown on plots
• 1985: entire site was deep plowed, limed and
  grass planted
• 1986: apple trees planted, ground cover
  maintained, mowed
• 2002: apple trees removed

• 1994 and 2001 (16 and 23 years later): soil
  samples collected and analyzed for PAHs,
  PCBs and PBDEs (PBDEs, non-detect) by
  Hale and Laguardia
                       Cornell Waste Management Institute
Old Orchard Sludge Plot




     Cornell Waste Management Institute
PAHs - Cornell Orchard (soil), Applied 1978
                                                    (soil),
                         PAHs - Cornell Orchard data applied 1978
                                 Laguardia and Hale


                   600

                   500
   ng/g, dry wt.




                   400

                   300

                   200

                   100

                     0
                                        1994                                  2001

                         phenanthrene          fluoranthene        pyrene
                         chrysene              benzo(a)pyrene      benzo(ghi)perylene

                                         Cornell Waste Management Institute
       Cornell Orchard (soil), Applied
PCBs - PCBs - Cornell Orchard (soil), applied 1978 1978
                                         Laguardia and Hale data

                   160

                   140

                   120

                   100
   ng/g, dry wt.




                    80

                    60

                    40

                    20

                     0
                                   1994                                      2001

                         PCB28   PCB52     PCB101     PCB138       PCB153            PCB180
           Syracuse NY. WWTP, 1972-73, PCBs 6600 ng/g           (Furr, et al,1976)

                                   Cornell Waste Management Institute
                  Conclusion



• PAHs, PCBs are persistent in Cornell
  Orchard 23 years after application
  – PBDEs below detection limit,
    consistence with estimated usage rate


        From LaGuardia, et al VIMS



               Cornell Waste Management Institute
    Long-term Effects of Sludge
            Application


• One dewatered sludge applied heavily in
  1978
• Cumulative metal loading ~EPA 503 limits
• Research
  – Effect on worms – 2003 field and laboratory


              Cornell Waste Management Institute
Orchard Sampling Locations and
    Extractable Metal Data




       Cornell Waste Management Institute
Looking for Earthworms




    Cornell Waste Management Institute
Number of Worms in the Field




       Cornell Waste Management Institute
Accumulating Organic Matter




       Cornell Waste Management Institute
    Reproductive Effects
on Worms: Experimental Data




      Cornell Waste Management Institute
   Risk assessments contain many
   assumptions and policy choices


Examination of Several Assumptions that
 Dramatically Impact Calculated Risks to
 Water Quality




            Cornell Waste Management Institute
    Different sludges and sludge products
               behave differently

Sludge variations
  Influents vary
  WWTP processes vary
Sludge treatment variations
   anaerobic digestion
   composting
   lime stabilization
   heat stabilization/pelletization
   alkaline soil amendment
              Cornell Waste Management Institute
What about Class A EQ?


No different than Class B EQ
Endotoxins

Nutrients

Chemicals

Odor potential
Note that processing mode impacts fate and
transport, odor potential, pathogens



          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
 Map of NYS Showing Relative Size of Watershed and Sludge
             Site Under 503 RA Assumptions
       Only 0.24% of watershed assumed to receive sludge.
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?



                                                       Watershed: 427,000 ha
      Example
                                                       Sludged Area: 1074 ha




                       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
       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
Sludge Products Behave Differently
                      Example:
     TCLP Leachability of Metals as % total metals




             Cornell Waste Management Institute al 1997
                                   Richards, et
Preferential Flow Paths
                 Blue dye reached 6
                   feet in 1/2 hour
                 Model would predict
                  ~3 years




    Cornell Waste Management Institute
    Comparison of Diet Used in EPA Risk Assessment and
                USDA Recommended Diet
         How Much Does the Home Gardener Eat?
1=EPA daily diet            1+2=USDA Recommended
Used Avg. ~1980 consumption Diet
Veg consumption has increased          About 2 x as much veg
Home gardeners eat high veg diet




1                                                              2




                     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
      Cd uptake into leafy veg, data from field studies
                           Cadmium uptake




Uptake value
used in 503--------
                           Cornell Waste Management Institute
                                            Cadmium Loading
Cadmium Calculation for Home Gardener
Eating Crops from Sludge-amended Soils
     Allowable Sludge Cadmium (ppm)
        120           EPA calc home gardener
     risk             (not the limiting path)
         39      503 limit (soil ingestion path)
     - - - - - - ----- - - - - - - - -
         15      simply changing to USDA diet
          5             changing to USDA diet
                      and arithmetic mean uptake
            1.5       changing to USDA diet
                      and 90th percentile uptake

Changing a few assumptions results in very different standard
                    Cornell Waste Management Institute
There is no such thing
          as
        “Safe”
  Rather what is the
  Acceptable Risk?
     To Whom?
Under what conditions?
     Cornell Waste Management Institute
                The Case for Caution
Because:
• Our ability to confidently predict risks from land
  application is very limited
   – Contaminants concentrate in sewage sludges
   – Many unevaluated contaminants in sludges (503 -only indicator
     pathogens and 9 elements)
   – Present standards are based on a risk assessment with many
     short comings

• Liability rests largely with the farmer
• If problems, hard to prove cause
• Enforcement and monitoring are inadequate
• Reports of illness
                    Cornell Waste Management Institute
Management Considerations Regarding
    Use of Sewage Sludges and
         Sludge Products




          Cornell Waste Management Institute
                 Setbacks

•   From homes, schools, etc
•   From wells
•   From groundwater
•   From bedrock
•   From watercourses/floodplains
•   Significant aquifers



            Cornell Waste Management Institute
             Application Practices


•   Incorporation - if yes, when
•   Pasture application
•   Food crops
•   Stockpiling
•   Soil type –permeability, steep, karst



                Cornell Waste Management Institute
          Legal/Administrative


• Indemnification agreement
• Record keeping
• Testing –frequency and/or parameters
  beyond 503?
• Archive samples
• Site specific permits for bulk application


              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
    capacity


                 Cornell Waste Management Institute

								
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