Application of Sewage Biosolids to Agricultural Soils in the Northeast: Long-Term Impacts and Beneficial Uses
Bowman, Dwight Cornell, Microbiology and Immunology
Harrison, Ellen Cornell, Waste Management Institute
Hay, Anthony Cornell, Microbiology (July 8)
Kim, Bojeong Cornell, Environmental Toxicology
Liotta, Janice Cornell, Microbiology and Immunology
Lucio Forster, Araceli Cornell, Microbiology and Immunology
McBride, Murray Cornell, Crop and Soil Sciences
Morant, Mervalin USDA-CSREES, Natural Resources and Environment
Laurie U of
John U of
Pfeffer, Max Cornell (July 8)
Richards, Brian Cornell, Bio and Env Engineering
Scherer, Emily Cornell, Waste Management Institute
Steenhuis, Tammo Cornell, Bio and Env Engineering
Wise, Abigail Cornell, Microbiology (July 8)
Zubris, Kimberly Cornell, Bio and Env Engineering (July 8)
Minutes of Annual Meeting:
E. Harrison welcomed the participants at 8:35 AM, and participants introduced themselves. E. Harrison reviewed the revised agenda.
“Copper, zinc and molybdenum soil tests for bioavailability”
Presenter: M. McBride, Cornell
Sources of copper include fungicides, dairy hoof baths, and sewage biosolids.
Most tests do not measure the toxic form -the free copper ion, Cu+2. Average soil concentration is 14-18 mg total
copper/kg. The suggested limit is 100
mg/kg. Some dairy soils and hog farms
are approaching or exceeding this recommendation. Toxicity concerns increase
with low soil pH and sandy soils.
Susceptible plants include corn and many grasses. Stunted plants, due to poor root system from
Cu2+, show wilt first in drought conditions.
Estimated 99% of copper is found in a Cu-organic matter complex, which
is thought to be less toxic. Different
soil tests for Cu are not directly comparable.
Mehlich 3, an aggressive test, is reported as ppm in soil. Toxicity is seen at 30 ppm. Morgan’s is less aggressive than Mehlich 3
and reported as lbs/acre in soil.
Mehlich 3 and Morgan’s are probably not related to bioavailability of
reported as mg/L in soil solution, measures the soluble fraction, but not
necessarily the toxic form. Cu2+
activity measures free copper which is directly toxic to the root. It is reported as pCu and toxicity is seen at
pCu. In the presence of a buffer (i.e. soil or sewage
biosolids matrix), detection limit is much lower than in a standard copper
solution. The electrode is put directly
into a slurry or filtered soil extract.
Most agricultural soils at pH 6 contain enough organic matter to provide
buffer. Tests can correlate copper
concentration to total soil concentration and pH, but cannot show what copper
is biologically significant.
Zinc. Sources of zinc include sewage biosolids, feed additives, and fertilizers. Zinc may be toxic to crops at high levels. Total Zn concentration in NY farm soils averages 75 mg/kg. A total Zn concentration greater than 200 mg/kg may be toxic, especially if the pH is lower than 6. Zn is extractable by Mehlich 3 but at amounts 100 to 1000 times the amount available to plants. Plant uptake of Zn is dominated by pH. (EPA Method 3051 reports total mineral except for silicate bound.)
Molybdenum. Sources of Mo include fly ash, sewage biosolids, and fossil fuel emission. Crops readily take up Mo if the pH isn’t low and toxic to ruminants at high forage levels. Water extractable levels predict crop uptake well. Total Mo concentrations greater than 2 mg/kg may be the limit for non-acid calcareous soils. Mehlich 3 causes Mo to precipitate and reabsorb due to the low pH.
- Cu and Zn extracted by Morgan's and Mehlich 3 tests are roughly proportional to total soil Cu and Zn
- Cu activity in soils, the most direct measure of toxicity to roots, is strongly related to pH
- total soil Cu and Zn are well above average in several livestock farm fields tested in NY, but no soils reached toxic limits as indicated by CaCl2 and pCu test
- corn stover Cu and Zn contents are well below phytotoxic thresholds on these farms despite high metals in some soils
- there is a poor correlation between commonly used soil tests and corn tissue composition
- a preferred soil test would extract "bioavailable pool" of trace metals
- hot CaCl2 better extracts the crop-available "pool" than Mehlich 3 or Morgan's
- for some trace metals, CaCl2 test provides a clearly better estimate of crop-available metal than Mehlich 3 test
A simple multi-element soil test for plant-available trace elements and heavy metals (0.01 M CaCl2 test), developed during this research, provides a quantitative basis for measuring deficiencies and excesses of these nutrients in soils. This test has the potential to reduce confusion associated with the array of tests presently in use for trace metals (e.g., Morgan's, Mehlich 3 ), tests which were not designed initially for estimating trace element availability. In fact, our recent comparison of the Mehlich 3 and 0.01 M CaCl2 tests revealed the latter test to be a more accurate predictor of crop uptake of metals such as Cd, Zn and Mo (McBride et al., 2003).
Our research on the residual
bioavailability of trace elements in land-applied sewage biosolids to important
forage crops in the Northeast, particularly forage legumes and grasses,
indicates that the element with the greatest potential for sustained uptake in
high-lime soils common in some of the most productive agricultural regions of
“Use of hot 0.01 M CaCl2 extractant to determine Mo availability and uptake by crops”
Presenter: Richard Stehouwer,
(See PowerPoint presentation, handout)
McBride asked if these experiments used established alfalfa? R. Stehouwer believes the stand is at least 2
years old, perhaps 3. E. Harrison asked
when does one sample?
Because Mo may be fairly readily soluble, is there a flush of Mo after
application? R. Stehouwer explained with
some sewage biosolids there is a flush, especially in higher pH material. M. McBride added that there is evidence that
bioavailability increases over 3 years (research at
“Long-term changes in Cd, Cu, and Zn solubilities and their total concentration in sewage-sludge amended soils”
Presenter: Bojeong Kim
(See PowerPoint presentation)
There is a lack of research on the behavior and fate of metals. The research involved 3 sewage biosolids products: dewatered-digested, alkaline-stabilized, and composted. Soil pH increased over time in dewatered-digested sample (due to lime addition during dewatering) in both Arkport and Hudson soils. Soil organic matter content decreased over time in both Hudson and Arkport soils. Free iron oxide did not change over time in either soil.
Conclusions: Temporal changes in the solubilities of Cd,
Cu, and Zn in both CaCl2 and EDTA extractions are observed, although
total metal concentration in the soils has not changed over time. Total metal concentrations in the Arkport
soils are lower than those in the
Discussion: B. Richards commented he has not seen
leaching to this extent. E. Harrison asked if there was any phytotoxicity
associated with treatments. M. McBride explained these treatments have low
metal loadings. They do not expect
measurable toxicity, but tests haven’t been run. Samples to do so are available.
“Cu accumulation in soil from dairy use of CuSO4 hoof baths”
Presenter: Rich Stehouwer.
(See PowerPoint presentation, PowerPoint handout)
Typo on slide 5: Cu in dry manure for farm 1 should be 297.
Objectives of this work included assessing patterns of CuSO4 hoof bath use, management and disposal practices on PA dairy farm; assessing the fate of Cu when hoof bath solution is added to manure management systems; and assessing fate and bioavailability of Cu when manure enriched with CuSO4 is added to soil. The three free stall operations studied, A, B and C, used hoof baths either daily, 4 to 5 times a week or 6 times a week, respectively. Total copper concentrations in the bath ranged from 0.8 to 1.5% Cu. (2.5% Cu is recommended.) During the past 10 years, farms A and B had increased the amount of Cu they use. All farms had a liquid manure system and spent hoof baths were dumped into the manure management system. Cu loadings for farms A, B, and C were 5.0, 1.5, and 2.1 kg Cu ha-1 yr-1, respectively. On farms with lower loading rates, you don’t see much accumulation, but in farm A, there is clearly some significant accumulation of Cu in 0-10 cm depth. (Note: Farms 1, 2, 3 on slide 4 are Farms C, B, A.) There is no evidence of Cu uptake from tissue analysis of corn silage for Farm A. The farm was spray irrigating with spray gun. Clean corn samples were taken from deep in the field outside range of spray gun. “Black corn” samples were taken from within the spray gun range. Farms spray irrigate several times during the season. When this sampling occurred, there was a very visible presence of spray. Unwashed black corn contains a very high concentration of copper- 102 ppm. The washed sample concentration is 30 ppm. It appears that there is not much uptake but there is some foliar presence/uptake. It is unknown if the Cu is absorbed or on surface. In silage process, unwashed black corn is mixed in with rest. Testing of silage is recommended. Incubation experiment data shows a very strong correlation between CaCl2 Cu and soluble organic C. This correlation does not hold up with Mehlich or Baker. As pH increases, there seems to be a correlated increase in CaCl2 Cu.
Conclusions: The bottom line is disposing of copper sulfate hoof baths in manure will increase the copper in the manure and copper will accumulate in soil where manure is spread. Soil copper could eventually reach levels that are toxic to crops or soil microbes, though for most operations this will take decades. Annual crop removal of copper will be around 0.5 lb/acre. Dairies adding less than 2 lb Cu acre-1 year-1 will have extremely slow accumulation. Dairies adding more than 5 lb Cu acre-1 year-1 will have more rapid accumulation and should consider taking steps to reduce amount of CuSO4 used such as cutting the bath concentration to 5% or lower and periodically testing soils and crops for Cu. Another recommendation is to put a clean water bath ahead of the copper sulfate bath to prevent fouling of the copper bath.
Discussion: E. Harrison asked about Cu supplementing and
rations. R. Stehouwer replied that
100-ppm is the maximum copper
recommended for dairy cattle. There is
some evidence that copper can accumulate in the liver at toxic threshold
feeding of 40 ppm but it depends on length of feeding and form of Cu. The concentration of Cu needed for control
(standard is 10%, testing may indicate 5% is suitable) and alternatives
(formaldehyde, zinc sulfate, organics) were discussed. It was noted that dairies in
Presenter: B. Richards
McBride and B. Richards were asked to put together an extension related
publication to issues of land-applied wastes, metals, and soil testing. They are looking for feedback on what
information would be useful and should be included. B. Richards reviewed the structure of the
paper. Trace elements were introduced
and the soil testing approach was reviewed.
Extractants were discussed. E.
Harrison asked if total acid digestion is what EPA means by “total metal”
tests. B. Richards replied that there is
an explanation of this in the text. It
was stressed that tests which were designed for a particular region’s soils and
uniform soil types may be inappropriate for other areas. Different tests results in state-to-state and
lab-to-lab variations. State-testing
labs are reluctant to change due to investment in current procedures. M. McBride commented that this investment was
on the macronutrient side. B. Richards
talked about bridging the gap with extractant to extractant correlations that
compound uncertainty and numerous analytical considerations. C. Elliot cautioned the use of soil tests for
other matrices. B. Richards presented a
table of recommended soil tests including the free ion electrode measurement
for copper. The expense of the Cu anion
electrode was discussed. Although the
electrode itself is not expensive, using different extraction methods for
different metals can be expensive. Hot
water CuCl2 (dilute unbuffered salt) extracts what is available to a
plant over 1 to 2 years while Morgan’s solution extracts what would be
available over a century. C. Elliot
asked about soil test for leaching. B.
Richards recommended dilute unbuffered salts.
A. Hay mentioned TCLP (toxic characteristic leaching procedure). R. Stehouwer said that
“Rational Phosphorus Management in Organic Residuals Recycling on Agricultural Land”
Presenter: C. Elliott
(See PowerPoint handout, PowerPoint presentation and Water Environment Research paper)
P is limiting factor in most freshwater systems that controls aquatic growth. When we are applying for nitrogen, we put on excess phosphorus. Excess P can lead to eutrophication. About 70% of P in PA waters originates from agriculture. Forty-seven states have adopted a P index approach to address the agricultural P issue, but most states have not explicitly considered sewage biosolids. (Note: In slide 8, STP stands for soil test P.) A rational sewage biosolids P management strategy should a) consider soil test P interpretation based on environmental risk; b) recognize buffer zone practices the mitigate P export; c) consider source P solubility differences; and d) consider P source phytoavailability differences. Sewage biosolids are very low in terms of water-soluble phosphorus.
Conclusions: P-based management will be imposed on sewage biosolids recycling. Sewage biosolids have not been explicitly considered in most state P Indices. P management policies will be deployed before the impact on sewage biosolids is fully appreciated. Sewage biosolids recycling programs will only be sustainable if rational, scientifically defensible P management approaches are adopted at the state level.
Discussion: The availability of P under saturated conditions (i.e. anaerobic) was discussed. Experiments conditions with rainfall simulators are not saturated and natural conditions may be worse than with simulators. C. Elliot replied that if P is bound with iron and the conditions are anaerobic, P is more soluble. But cautioned that we’ve ignored P in the past and be careful about being extreme in the other direction. Runoff was discussed and its dependence on geography and buffer vegetation.
Presenter: A. Wise
Alkylphenols are intermediates from anaerobic
biodegradation of alkylphenol polyethoxylates (APE), a widely used class of
nonionic surfactants. Estrogen receptors
recognize alkylphenols as estrogen, which can result in feminization of male
trout, changes in sex ratio and reduced hatching rates. Nonylphenol has been found in water, indoor
air, and food. This work was done to
determine if there are seasonal trends associated with AP concentration in sewage
biosolids in the central NY region. All sewage
biosolids used was from anaerobic digesters.
Results show seasonal trends vary between sites. L. Osher asked why would you suspect seasonal
differences? A. Wise replied that in
terms of biodegradation, studies show temperature dependent
biodegradation. Perhaps as temperatures
increases, nonylphenol (NP) and octylphenol (OP) concentrations will
decrease. In order to compare NP and OP,
one must look at the estrogenic potential.
OP is 20 times more potent than NP.
Average OP concentrations are converted into adjusted OP. Of all sites, only
Conclusions: There appear to be local seasonal NP and OP trends. There does not appear to be a universal trend for NP or OP across 3 plants. Local sewage biosolids concentrations of NP and OP are significant.
Discussion: E. Harrison asked if the levels of triclosan (an antibacterial) were high enough to affect the sewage treatment plant? A. Hay replied that 20 to 80% is removed resulting in an amount below the effective concentration for bacteria. The effluent range is toxic to the more sensitive freshwater algae. Natural estrogen compounds were discussed. They were not investigated in this research and there is no published number for background numbers in soil. From research regarding estrogens in poultry manure applied to land, some background numbers were found but they were incredibly low. 17β estradiol is found in dairy manure at 1 ppm.
The potential to develop recommendations for land application of sewage biosolids relevant to the NE and addressed to farmers, farm advisors, regulators, local governments and others was discussed.
Participants agreed to each
gather information on how their state/provincial rules and requirements are different
There were several items that the meeting participants tentatively agreed upon. (Nothing will be “final” until the further discussions are held.) :
Is direct ingestion by ruminants a concern?
had no formal recommendation to present, but as indicated in talk, the
cumulative loading approach for regulating Mo is not really workable. It would be better to go to some type of soil
test, but we’re not at a point to recommend what that test could be. If we were to go with CaCl2
extraction, what would be the threshold or guideline to use? M. McBride noted the differences between his
and R. Stehouwer’s recent Mo work; M. McBride looks at soils that have had
applications in the past and Stehouwer looks at short-term situations. M. McBride showed results from the
E. Harrison commented that there is
no federal standard for Mo and the government is talking about going with
40-ppm sewage biosolids
concentration. (B. Richards and R.
Stehouwer noted there is a ceiling concentration number of 75 ppm.) M. McBride
B. Richards asked if, because there
is only a ceiling limit in place, a single load of sewage biosolids could put you over the threshold? M. McBride
said yes. A. Hay asked if there are sewage biosolids that are that contaminated? M.
McBride said the
R. Stehouwer recommended not allowing the soil pH to go above 7 or 7.5. This can be a concern when advanced alkaline stabilized sewage biosolids is spread. C. Elliot commented that N-Viro is a particular problem if it is applied according to N because it contains very low nitrogen and very high alkalinity. A. Hay said farmers are overusing N-Viro because the long-term neutralizing capacity isn’t there.
E. Harrison said U. Krogmann sent a
E. Harrison said M. McBride mentioned
that there are analytical issues with using total
2. Recommendations: Organics. A. Hay
A. Hay recommends funding more research. What are the target organisms? We have some evidence that there are reduced earthworm counts. We have PCBs and dioxins in plots. But toxicity to earthworms doesn’t coordinate with presence of organics. The ability to regulate contaminants in soil versus water was discussed. D. Bowman said enforcement is basically water. You need to find out about leaching.
3. Recommendations: Nutrients. C. Elliot and R. Stehouwer.
C. Elliot recommended more frequent
nitrogen analysis. R. Stehouwer said
when calculating N loading rates there’s a very large potential error
associated with ammonium. Even though it is small amount of total N, can account for large of
amount of error. If you want to
tighten up on N loading, more frequent analysis of N and ammonium would
help. An inexpensive improvement would
be to use an ammonium electrode.
Stockpiling and the loss of ammonium were discussed. For corn, R. Stehouwer recommended cutting
back on loading of N and relying on presidedress nitrate test (PSNT) in the
spring. D. Bowman commented on the farm
insurance program set up by the USDA to reduce excess N and P application. R. Stehouwer said many small treatment plants
in PA are doing annual analysis. Link
this testing to when the sewage
biosolids are moved to the farm and spread i.e. if the plant has been
storing sewage biosolids all
winter don’t run the analysis until it is moved. D. Bowman commented on a
Ellen asked for recommendations regarding P? E. Harrison asked if water-extractable instead of total P should be tested? C. Elliot said yes, WI is already doing this. But it won’t make a difference if there is no source coefficient in a state’s P index. The solubility of P in bio sewage biosolids solids varies widely. He added that there is no compelling reason that dairy farms should use sewage biosolids.
4. Recommendations: Metals. M. McBride.
.McBride said the original EPA list
of metals in sewage biosolids
was 10. At this point, a number of these
(nickel, arsenic, chromium, selenium) are not major issues. Lead, mercury, and cadmium have been reduced
over time due to pretreatment and industry moving out of the
Re phyto toxic metals, C. Elliot and M. McBride were part of a group that came up with Guidelines in 1985 which were far lower than the levels EPA came up with for the 503. Do the recommendations from 1985 still hold or is there additional knowledge that would change conclusions? M. McBride said he still defends the copper and zinc limits. The nickel recommendation may be more cautious than it needs to be. C. Elliot said if you’re talking about corn and some other field crops and the pH is controlled, the 503 numbers are okay. But doesn’t cover the range i.e., sensitive crops on coarse textured soils. R. Stehouwer said that in most cases in a well-managed agricultural field, you’re probably okay. If that’s going to be converted to vegetable crops, levels are probably high. Plants with varying root depths are affected differently. Greenhouse and metal salt addition studies were discussed. M. McBride said the EPA says not to use greenhouse studies because roots are forced to take nutrients from contaminated soil and root avoidance can’t be seen. The 1985 guidelines used salt studies. McBride suggested that after ~5 years, salt study results would be valid.
Cornell Field Crop Guidelines give recommended soil concentration limits that echo the 1985 guidelines. U. Krogmann indicated that NJ is similar. C. Elliot recommended a blanket cautionary comment about vegetable crops, though recognize that with 503 application limits, it will take awhile to get up to excessive cumulative applications. Could we suggest soil-based limits for elements are dependent on crop type? A. Hay asked if we could go to CaCl2 extractable and do away with soil types? M. McBride said this is possible with enough data, which we don’t have. This could not be done with copper because phytotoxicity depends on activity. R. Stehouwer said it’s going to take a long time for farmers in PA to reach the limit for Cu, 60 to 100 ppm depending on soil type, with sewage biosolids. M. McBride said we have some dairy and chicken farmers that are exceeding 130-200 ppm limits for zinc. R. Stehouwer recommended periodic soil testing and if levels get too high, do some tissue tests. B. Richards recommended both CaCl2 extraction (a current snapshot) and total (what could happen if the pH changes). E. Harrison suggested if you reach levels that are in the 1985 publication, you should stop applying sewage biosolids.
5. Recommendations: Water Related Issues. B. Richards.
B. Richards said the primary concerns with surface water are the presence of pathogens and/or nutrients. He discussed the idea of variable source area hydrology and preferential flow (http://www.bee.cornell.edu/swlab/soilwaterweb/index.htm). Runoff is generated in predictable wet spots. The management recommendation is to avoid spreading on these areas when runoff is likely to occur, typically the spring. Hortonian thinking was don’t spread on slopes. Now we have a different set of recommendations. Slopes may be the best places to spread.
There are issues with stockpiling in areas with shallow groundwater. A study done last year with very low cumulative loadings showed water quality effects. We can detect signals, though they are extremely difficult to see. J. Peckenham added that preferential flow is very important with chelated metals that move very early. There are issues with seasonal high water tables that usually occur when the material is being spread. We’re not sure how much surface water is communicating with groundwater. When we see heavy loading, we see biomass growth. As the vertical flow space is plugged by biomass, we see horizontal flow. L. Osher said we’re talking about transport issues. The criterion of slope doesn’t really fit. More research is necessary on a regional scale or state level. If you’re going to develop an index, these transport processes need to be looked at. J. Peckenham said the dimension of scale has not be addressed i.e. field vs. pile vs. watershed. What’s the right scale to manage this at? How do you manage at a scale larger than the field? .
Elliot said setback issues need to be addressed. Regulations only say 10 meters. They don’t say what you do in these 10 meters. The idea is you leave the setback distance in a natural vegetative state and don’t farm right up to the water. L. Osher recommends having the regulations for both sewage biosolids and fertilizers correlate. Brian said it makes sense to integrate sewage biosolids nutrient management with manure management. C. B. Richards would like to say something related to groundwater but is uncertain how to frame it. D. Bowman does not have current data on the potential for viruses to move through groundwater.
Action: Each participating state/province will provide information on required management practices in their locale. E. Harrison will compile these to serve as the basis for a group discussion (conference call).
Federal regulations require a
10-meter setback from watercourses.
State regulations were discussed.
Elliot said if you get a permit to
spread sewage biosolids in
PA, you must have and implement a conservation plan that includes not only soil
and erosion but also nutrients. L. Osher said that
The future of the Multistate Project.
Based on the discussion summarized below, the group decided that we will not develop a proposal for renewal as a multi-state research committee, but will seek to become a coordinating committee. The topic the committee would address is “the use of soil as a waste disposal medium,” enabling us to address a broad range of residuals and land uses. We would continue to focus on the north east.
The difference between a
coordinating committee and a multistate research committee was defined. To be a multistate research committee, you
must write a proposal that gets approved by the USDA without direct
funding. You then have reporting
requirements. A coordinating committee
does not go through these hoops, but would meet annually. C. Elliot and R. Stehouwer participate in the
W-170 group that has a similar project. They are a year ahead of us in the renewal
process. Following discussion about a
possible unification of the groups, it was determined that W-170 would proceed
and NE-1001 members are free to join. E.
Harrison suggested we move to be a coordinating committee, as the framework of
a proposal isn’t that helpful. M.
Pfeffer said that the NE experiment station directors are scrutinizing
proposals more and more, especially for multistate research projects. There is a critical eye toward continuation
projects. Thus being an existing project
could be a handicap. The bar is lower
for a coordinating committee. Most
experiment stations would encourage conversation and collaboration. R. Stehouwer agrees that a coordinating
committee makes sense. C. Elliot argued
for the coordinating committee due to the potential duplication of objectives
with W-170 which would also make USDA approval less likely. L. Osher said that in certain states it’s
essential to be a multistate to get money from colleges. In
The next meeting was discussed. The end of June worked better than July. L. Osher has a biannual meeting that is usually the week of June 20th.
“Water Quality Impacts of Sewage Biosolids as Landscape Amendments”
Presenter: L. Osher,
biosolids are used to construct architect’s topography and provide
planting beds for vegetation, commonly on resorts and private estates. Sewage
biosolids are inexpensive (compared to “topsoil”) and used in
conjunction with irrigation systems. In
Conclusions: Biosolid additions to soils result in increased nitrate and ammonium leaching after application. In general, NO3- leaching was much higher than NH4+ indicating a well-aerated environment. Trace element leaching is higher under biosolid treatments than under natural soils or topsoil additions. Greatest losses of nitrate and ammonium and trace elements are from mixed treatments. All trace elements concentrations are below EPA drinking water standards
Discussion: B. Richards asked if pH profiles were looked at in terms of leachate. L. Osher said no. M. McBride asked if silicate sand or carbonate sand was used because carbonate sand could explain the barium. L. Osher guessed that it was more silica due to glacial till soils and glacial outwash. B. Richards said the packed columns lead to conservative estimates of leachate and that actual leachate would be much greater in the field. E. Harrison asked about the levels of compounds in the sewage biosolids. Laurie said it’s so variable. Plants present data every year but receive sewage biosolids from many different areas. The compost gets tested every month. B. Richards asked when loadings of this magnitude were started. L. Osher replied it has been the practice for at least a decade. Unity (the compost supplier) doesn’t have a client list, but all of the landscaping contractors she’s spoke to use this material. J. Peckenham added that mine reclamation uses up to 1 meter of sewage biosolids and everything you don’t want in the groundwater is showing up mobilized. B. Richards said that after 6 to 8 years, some phytotoxicity due to metals is showing up in greenhouse studies (eternal summer). He would suspect that the rate of plants dying would start to pick up.
Presenter: Kimberly Ann V. Zubris,
(See PowerPoint presentation)
Synthetic fibers are easily
detected in sewage biosolids
effluent using polarized light microscopy.
Fibers must be present in sewage
biosolids products that have been processed in several different ways
and applied to land. Fibers in dewatered
digested sewage biosolids
were long and obvious. Fibers from
pelletized sewage biosolids
were imbedded in sewage biosolids
materials. Fibers in N-Viro sewage biosolids were small and
brittle due to the high pH. Fibers in
composted sewage biosolids
were stuck in big particles and not as easy to find them because of extraction
difficulties with wood chips. Greenhouse
studies showed no fibers in the control and fibers in the sewage biosolids-applied
soils. Old-site studies also showed no
fibers in the control and fibers in the site-soils. B. Richards said application was about 200
tones at the old-site. Future work
includes studying archived soils and determining quantitative methods. Studying sites with lighter loading and
variations in loading on one site (
“Considerations for Dairy Farms Regarding the Use of Sewage Sludges, Sludge Products, and Septage”
(See handout, report)
(Note: Slide 4, typical level of sewage biosolids should read 7000-12000)
In NYS the largest users of sewage biosolids are dairy farms. A document was written to help farmers and advisors make informed decisions regarding the use of sewage biosolids and to minimize risks associated with sewage biosolids application.
Discussion: Why farmers are using sewage biosolids at all was discussed. Certainly money figures in as some farms get paid to take the material. Cash crop farmers generally don’t want to take it because they don’t have the equipment to begin with. Dairy farmers are used to dealing with manure and get some sort of compensation, even though they aren’t told about the drawbacks. Additionally, N-Viro is a source of lime for $4/ton applied. Typically, lime is $25/ton applied.
Presenter: J. Peckenham
(See PowerPoint presentation, handouts of stockpile study)
The University was asked to provide
neutral input to a public debate on sewage
biosolids, make research accessible, and demonstrate the validity of
regulations. The report will establish a
baseline for debate, characterize sewage
A leachate study was conducted. Lined cells were built with an underdrain and side gutters to look at shed precipitation and leachate. No shedding was observed. After two weeks, leachate flow was generated and was fairly constant. Extremely high ammonium loads were observed. High metal-chelating DOC loads were seen. Biological growth was observed. Pathways become filled with biomass and clog macropores, resulting in lateral movement.
Presenter: D. Bowman
(See PowerPoint presentation)
Pathogens of concern include viruses (those not encapsulated), bacteria (those that survive well or form spores), protozoa (mainly in effluent stream), and helminthes (mainly in solids stream). Class B sewage biosolids contain the eggs of helminthes, probably Ascaris lumbricoides. Class A sewage biosolids must be tested to verify that Ascaris lumbricoides eggs, salmonella, and the poliovirus are destroyed. The process is tested, not the specific compost. Routine chlorination does not routinely kill Giardia and Cryptosporidium that are not degraded by the aeration treatment of the water. Most protozoa are found in large numbers. Giardia/mouse (plant pilot) studies show UV treatment of treated effluent will provide > 3 log reductions in viable cysts, chlorine dioxide treatment of the effluent will provide > 3 log reductions, and municipality now looking at combination treatments to push the value to 4 logs of reduction. Ascaris/UV work was done because of concern that foodstuff will be contaminated with human pathogens. Ascaris is more difficult to kill than other pathogens and can be used as a “worse case scenario” organism to test processes. Research shows tanned Ascaris eggs with an outer coat, the stage passed in feces, are much more difficult to kill with UV than either Cryptosporidium or MS2 phage. Curves have been generated that can be used to assess parameters needed for food safety. Future sewage biosolids work includes examining the use of Sentinel Chambers for determining the production of Class A material, examining the possibility of using ATAD-Class A sewage biosolids as a base for green mulch seeding material, and examining surrogates for ability to replace Ascaris eggs in proving processes are Class A in full-scale systems.
M. Morant. See handout on funding opportunities.
In August the 2004-2005 programs will be coming out. It would be useful for the NE group to meet with USDA NRI staff to let them know our view of the important research issues to try to influence how the funding is distributed and what the RFPs address. Impacts and money saved are important considerations for USDA.
Investigation of Health Complaints and Aerosols
E. Harrison. WERF has decided to fund research into “rapid response” to the reports of illness as associated with land application. It will involve “affected stakeholders” i.e. people who are reporting illness and scientists who have been more cautionary as well as industry and municipal generators.
E. Harrison. EPA ORD out of
Roundup and metal leaching
M. McBride. Current research will look at ability of Roundup to mobilize copper in soil. Roundup is a chelator and drags copper into solution. Farms are spraying 2-3 times the recommended amount due to resistance. Home use has an even higher application rate.
Canadian metals in the environment
Maine Sewage Biosolids projects
Sewage Biosolids Projects
for Environmental and Watershed Research
Stockpiles and Nitrogen Leaching (
· Lined cells and lysimeter plot
· Quantify nitrogen loss in field
· Quantify nitrogen species
· Complete, publications in progress
Metal Leaching and Transport from Sewage Biosolids (USGS)
· Companion study to stockpile nitrogen
· Lysimeters and shallow piezometers
· Facilitated metal transport (early and fast)
· Field work completion 2004, publications in progress
Metal Leaching and Transport from Sewage Biosolids in Soils (USGS)
· Column studies
· Characterize partitioning
· Characterize DOM
· Lab work in progress, publications in 2005
Metal Mobilization from Land Reclamation Using Sewage Biosolids (in Prep)
· Significant metal mobilization beneath reclaimed gravel pits
· Lysimeters and shallow piezometers
· Elevated DOC loading
· Full proposal in preparation
Organic Wastes and Drinking Water Quality (pending USDA)
· Watershed scale loading of DOM to surface water
· Disinfection By-Product Formation Potential
· Assess impact to groundwater
· Proposal in review
Brandt, R. C., H. A. Elliott, and G. A. O’Connor. 2004. Water-Extractable Phosphorus in Biosolids: Implications for Land-Based Recycling. Water Environment Research. 76(2): 121-129.
Elliott, H. A., R. C. Brandt, and G. A.
O’Connor. “Rational Phosphorus
Management in Organic Residuals Recycling on
Harrison, E, L. Telega, M. McBride, S. Bossard, L. Chase, D. Bouldin, and K. Czymmek.
“Considerations for Dairy Farms Regarding Use of Sewage Sludges, Sludge Products, and Septage.” PowerPoint presentation for NE-1001 2004 meeting.
Harrison, E, L. Telega, M. McBride, S. Bossard, L. Chase, D. Bouldin, and K. Czymmek. 2003 “Considerations for Dairy Farms Regarding Use of Sewage Sludges, Sludge Products, and Septage.” Cornell Waste Management Institute publication.
McBride, Murray and B. Richards. “Testing soils for trace metals from land-applied wastes.” Working paper for NE 1001.”
M. Morant. “CSREES Update” Handout for NE-1001 2004 meeting.
Qureshi, Shabnam, B. Richards, A. G. Hay, C. C. Tsai, M. B. McBride, P. Baveye, and T. S. Steenhuis. 2003. Effect of Microbial Activity on Trace Element Release from Sewage Sludge. Environmental Science and Technology. 37:3361-3366.
Qureshi, Shabnam, B. Richards, M. B. McBride, P. Baveye, and T. S. Steenhuis. 2003. Temperature and Microbial Activity Effects on Trace Element Leaching from Metalliferous Peats. Journal of Environmental Quality. 32:2067-2075.
Qureshi, Shabnam, B. Richards, T. S. Steenhuis, M. B. McBride, P. Baveye, and S. Dousset. 2004. Microbial acidification and pH effects on trace element release from sewage sludge. Environmental Pollution.
Richards, Brian, B. M. Schulte, A. Heilig, T. S. Steenhuis, M. McBride, and E. Harrison. Environmental impacts of applying manure, fertilizer, and sewage biosolids on a dairy farm. Journal of the American Water Resources Association. V. 40 p. 1025-1042.
Stehouwer, R. “Cu accumulation in soil from use of CuSO4 hoof baths” PowerPoint presentation for NE-1001 2004 meeting.
Stehouwer, R and M. McBride. “Use of hot 0.01 M CaCl2 extractant to determine Mo availability and uptake by crops” PowerPoint presentation for NE-1001 2004 meeting.