Connecticut Nutrient Management
Many different types of animals contribute to the over-all nutrient surplus in Connecticut.
However, an analysis completed by the University of Connecticut indicates that dairy and
poultry farms produce approximately 68% of the State's manure. This analysis is based on
animal census data developed by the U.S. Department of Agriculture (USDA). Subsequent
analysis of the data shows that the majority of the dairy and poultry populations are concentrated
in four areas throughout the state. The percent of available land required for agronomic
application of nutrients produced by the dairy industry, the dairy and poultry industry, and all
animal sources, was compared on a county-by-county basis. This data assumes that land available for nutrient application is all grassland and corn fields listed in the crop census.
A surplus of nutrients is theoretically indicated when greater than 100% of the available land is
needed, however, a nutrient surplus can also occur at lower percentages. Not all of the grassland
and corn fields are available for land application of manure due to proximity to sensitive water
bodies or nearness to neighbors. In addition, some land already has a surplus of phosphorus
which would prohibit further application of manure and could preclude further land application
for many years.
From Table ES-1, the counties where the dairy and poultry farms contribute significantly to the
nutrient surplus are evident. Generally, dairy and poultry CAFOs, are currently using all
available land for manure application in their surrounding areas. Table ES-1 indicates significant
surpluses in New London, Tolland, Litchfield, and Windham Counties. Addressing the nutrient
surplus in these areas is the focus of this study and the CAFO farms in these counties will likely
be directly affected by the DEP CAFO General Permit.
In counties such as Fairfield County, Hartford County, Middlesex County and New Haven
County, more than 60% of the manure produced is from non-poultry and non-dairy sources. In
these counties other animal sources contribute significantly to the total amount of generated
nutrients. However, none of these animal operations have sufficient numbers of animals to
subject them to the requirements of the DEP General Permit.
This study focused solely on the dairy and poultry CAFOs in the State of Connecticut. There is
significant variability in the sizes and location of farms in Connecticut. Dairy farms are widely
dispersed throughout the state. By mapping the dairy animal density in the State, four areas with
high animal density were identified. They are located in Litchfield, Tolland,
Windham, and New London Counties. These regions of the State would be more suited for
regional manure management solutions while the remaining areas are better suited for individual
farm manure management solutions. Conversely, the majority of the CAFO poultry operations
are located in New London County. Since the poultry facilities are already quite large, a separate
regional facility was not considered.
For the regional dairy design basis, the animal density mapping was used to calculate the number
of dairy cows within each of four areas of highest concentration. These numbers were further
refined by assuming that one-third of the animals would be part of the replacement herd and that
fifty percent of the remaining cows would be participating in a regional facility. This analysis
resulted in a regional facility managing the manure from 2,500 animals. To account for the
possibility that the regional facility would also process food wastes, an additional 500 animals were added to approximate the equivalent nutrient and solids loadings from food wastes for a
total of 3,000 animals.
As the CAFO regulations potentially apply to all farms with greater than 200 head, the individual
farm size was set at a 200 animal basis.
Density of Dairy Animals in Connecticut Map
In order to prevent the over-application of nutrients onto the grassland and corn fields
traditionally used for dairy and poultry manure application, the nutrients will need to be
converted into a form and/or product that can be exported off the farms. There is already an
established market in Connecticut for both inorganic and organic based fertilizers. However,
raw manure cannot compete with the products currently available. Raw dairy and poultry
manure tends to contain a high amount of weed seeds, odor and pathogens. An acceptable
product must be generated without the weed seeds, pathogens, and odor using cost effective
technologies. The following products meet this criteria and can be generated by treating raw
dairy and poultry manure:
· Anaerobic Digestion Effluent
· Poop Pots
· Ash from Combusted Manure
Redistribution of dairy and poultry manures to other market sectors would significantly reduce
the amount of nutrients contributing to the State nutrient surplus. A percentage of the manure
produced will still need to be utilized as fertilizer in area crop land. Therefore, it is not necessary
to move all manure to other sectors. Land application would still need to occur on area
farmland, only in a smaller more manageable volumes to meet the agronomic application rate
A wide range of technologies were reviewed and screened for their technical feasibility and their
ability to transfer nutrients to a form that facilitates moving nutrients off-farm. The screening of
these technologies resulted in the development of a technology short-list for dairy and poultry
manure management. These short-listed technologies include:
· Liquid/Solids Separation
· Anaerobic Digestion
· Chemical addition to precipitate phosphorus
· Production of alternative products such as horticultural pots and paper.
For the most part, these technologies have been implemented in the United States and overseas at
full-scale facilities for manure and/or residuals management, and are appropriate for either a
local or regional manure management solution.
For the purposes of the study, the technology options listed above have been organized into
nutrient management scenarios for individual farm and regional facilities. In order to easily
compare the technologies under consideration, tables were developed listing each option and
evaluation parameters. The individual dairy farm options, regional dairy manure facility options
and poultry manure options are discussed below.
Individual Dairy Farm
Three options were considered for the individual dairy farm:
· use of liquid/solid separation,
· composting whole manure, and
· liquid/solids separation followed by chemical precipitation of phosphorus.
Many of the parameters reviewed had the same impacts with each of the three options
considered. Air Emissions Impacts are neutral, no renewable energy is produced, and
greenhouse gases and criteria air pollutants are the same as existing manure management
methods for all of the individual farm options considered. Table ES-2 summarizes the remaining review parameters for the dairy manure farm options.
It should be noted that liquid/solids separation does not necessarily move any nutrients away
from traditional land application. However, it does allow different application methods to be
used and creates the potential of exporting solids to another market. It may also allow a greater
percentage of the grasslands and corn fields to be used for land application by allowing the use
of liquid injection application methods which generate less odor than surface application
methods. By comparison, whole manure composting has the potential to move all of the
nutrients away from traditional land application and chemical precipitation has the potential to
move a majority of the nutrients off-farm as a phosphorus rich precipitate.
Regional Dairy Manure Facility Options
Three options were considered for the regional dairy manure facilities:
· composting dewatered manure (assuming dewatering occurs at the individual farm),
· anaerobic digestion of the whole manure followed by liquid/solid separation and
composting of the solids, and
· anaerobic digestion of the whole manure followed by liquid/solid separation, chemical
precipitation of phosphorus and composting of the manure solids and phosphorus
All of these options are technically feasible and have the potential to move 50% or more of the
nutrients to other markets. The option using chemical precipitation could potentially move up to
92% of the phosphorus to a different market. The composting only option is neutral to air
emission impacts, reduces water pollution impacts and does not create any renewable energy.
The two options with anaerobic digestion can produce renewable energy and should be able to
meet Connecticut Class I Renewable Portfolio Standards but must apply for such a designation.
Since the digester gas will be burned, there will be an increase in criteria air pollutants but they
will fall within the State's emission limits. Anaerobic digestion will decrease the odor produced.
These options will all reduce water pollution impacts. Table ES-3 summarizes the remaining
review parameters for the regional options.
Poultry Manure Options
Two options for poultry manure operations were considered: one, co-combustion of the manure
with waste wood and two, composting of the whole manure. No distinction was made between
individual farm and regional facilities for poultry manure since the individual farms are of the
same size as a regional facility. Both options are technically feasible. Costs were not available
for the co-combustion option so a comparison of costs was not done. The co-combustion option
is being pursued privately at the time of this study.
Co-combustion of poultry manure generates ash, power, steam and heat. The ash is high in
phosphorus and can be a saleable product. The power, steam and heat will be used at the farms
for the egg processing facility. This renewable energy should be able to meet Connecticut Class I
Renewable Portfolio Standards but an application must be filed to apply for such a designation.
The co-combustion option will generate criteria air pollutants due to the combustion process.
However, these can be controlled to meet air quality criteria. This option will reduce water
pollution since all of the manure nutrients will be moved to another form.
Similarly, composting will have a positive impact on water pollution since compost is a slow
release fertilizer and is less likely to leach into surface or groundwater than inorganic forms of
fertilizer. Odor is generated in a composting process but can be controlled with appropriate odor
control equipment. Table ES-4 summarizes the remaining review parameters for the poultry
IMPACTS ON NUTRIENT SURPLUS BY MANURE MANAGEMENT OPTIONS
The management of poultry manure in New London County has the single largest impact on the
reduction of nutrients statewide. Managing poultry manure in New London county is estimated
to reduce the statewide nitrogen load by an amount equal to 43% of the available area and the
phosphorus load by an amount equal to 87% of available land. The next largest impact would
come from implementing four regional dairy manure composting facilities within the highest dairy density areas in the State. Implementing these facilities is estimated to
further reduce nitrogen and phosphorus by approximately 14% and 15%, respectively.
The priority in terms of impact on the nutrient surplus would be to implement poultry manure
options followed closely by implementing dairy manure options for the regional facilities. The poultry farm option currently moving towards development is the co-combustion option. This
option is being developed privately, therefore the cost information in not publicly known. If all
CAFO sized poultry farms choose to use whole manure composting, the overall capital cost
would be roughly $17.5 million per million birds, or a total of $79 million for the 4.5 million
birds at CAFO farms.
Since it is not possible to predict which CAFO dairy farms will choose to be involved in the
regional facilities, the costs of implementation have been estimated for regional facilities and all
CAFO dairy farms. There will be some overlap between these two categories but it should be
noted that a large portion of CAFO animals are outside of the assumed regional facility areas.
Assuming that all four regional facilities are built and operated, the overall capital cost will be
four times $2.65 million or $10.6 million. If all CAFO sized dairy farms choose to use whole
manure composting, the overall capital cost would be roughly $980,000 per two hundred cows.
With 19,457 cows currently associated with CAFO farms, the total capital cost for all CAFO
farms will be $95.4 million. It should be noted that these costs are in 2005 dollars and do not
take into account future construction cost inflation, which is currently estimated at 5 to 6% per
RECOMMENDATIONS FOR IMPLEMENTATION
The goal of this study was to identify economically and technically feasible manure management
methods for the dairy and poultry farms to manage manure from CAFOs in the State of
Connecticut. While technically feasible options were identified, the capital and operating costs
for all the options are high, considering the economics of dairy and poultry farms, and may
preclude their implementation. Successful implementation of the CAFO General Rule must
include maintaining viable local farms while addressing nutrient issues. Providing funding
assistance will be critical to this end.
Based on the ability to impact the nutrient surplus in the State, the focus should be on
implementing the poultry manure co-combustion option and regional dairy composting facilities.
Towards this end, the following is recommended.
· This report should be used to educate legislators on the importance of adequate funding
for the waste management needs of the CAFO farms in Connecticut. When the CAFO
General Permit is issued, there needs to be sufficient funding support in place for the
· Work to develop policies, incentives, and funding assistance which tie nutrient
management solutions to the benefits of maintaining agricultural operations throughout
the state. These benefits include potential for renewable energy production, open space
maintained by farms, food security provided by having local (in-state) producers, reduced
costs to the state and towns by maintaining farms (less housing development, therefore
lower school costs etc), the economic contribution farms provide to local and state
community (i.e. other businesses and jobs dependent on the existence of farms) and
maintenance of strong local communities and cultural heritage (as farmers are tied to the
land and communities).
· Farmers in Connecticut could use additional support in developing options that are well
suited to their specific situation. This assistance would include funding for pilot tests of
dewatering equipment or demonstration projects of small scale composting.· Work to add anaerobic digestion of agricultural residuals and co-combustion of manure
to the Connecticut Class I Renewable Portfolio Standard.
· State and Federal agencies should develop policies and incentives for nutrient export
(inter-regional) to transfer manure and related by-products, such as compost, to alleviate issues of excess nutrient on one region and reliance on commercial inorganic fertilizers in
There are several areas in which the DEP or other State Agencies or local organizations can work
to move forward alternative manure management methods. These include the following:
· Work with the groups in the North Canaan area, the Woodstock area, the Ellington area
and the New London area to develop and assess interest in a regional facility.
o Involve all dairies in the area early in the process to foster interest and support.
o Obtain "seed" funding to start the development process in each area.
o Identify a local sponsor organization.
o Proceed with site selection and preliminary design once the preliminary
organization and initial development funding has been secured.
· Technologies to track and/or test that are not ready for full scale implementation
o Dewatering Options
- Pilot testing of screw press technology for dairy manure at interested farms.
Manufacturer's guaranteed solids capture rate based on pilot testing data. Also, at
least one manufacturer has stated that they will not sign contracts with individual
farmers. Therefore, CT DEP or other entity will need to fund and spearhead any
pilot testing program.
- The Jannanco dewatering system shows promise but they have not yet published
their results. If they are able to capture a high percentage of solids in a relatively
high solids content cake, this will make composting facilities at individual farms
smaller and more cost effective while still removing a large portion of the
- Development of high recovery dewatering - Tinedale in Wisconsin. Regional
facilities may obtain higher nutrient removal by using a high recovery dewatering
system. Such a system requires a review of higher technology options and a
conceptual design caparison of the options.
o Poop Pots or paper production show good potential as nutrient removal mechanisms.
Testing should be done to determine the nutrients removed in the pots or paper and
provide assistance in the scaling up of the current technology to a full scale
o Phosphorus Precipitation - Conduct pilot testing to determine appropriate chemical
dosing requirements. Get chemical supplier and equipment vendors to help
determine proper alum dose on representative manure samples.
Facility Siting, Operations and Commodity Sales
· Site regional digester or co-combustion facilities near power/heat users who would be
willing to purchase power directly from the regional facilities.
· Work with local planning and zoning boards and inland wetlands commissions to review
plans for regional facilities.
· Farmers have expressed a need for assistance in marketing any products from manure
such as compost. There are several methods to acquire this assistance:
o Hire a compost broker. There are several organizations currently marketing
compost for other compost producers in the New England area. Compost brokers
have contacts with groups trying to purchase compost and are able to match the
level of compost quality with the needs of compost users. They work in several
ways: either charging a fee, or collecting a portion of the sales or both. Compost
brokers will charge a fee to cover their marketing cost and to generate a small
profit. Therefore, the money that the composter would receive from the sale of
the compost would be reduced.
o Develop Marketing assistance through CT Dept of Agriculture similar to the
existing group which promotes CT grown products. This approach could be
implemented to help farmers market their compost without having to pay as much
for marketing. It would help the farmers keep a greater portion of the compost
sales and thus make this method of manure management more feasible.
The next steps in regional facility development and individual farm solutions include
development of feasibility studies for specific sites and situations, development of business plans
and preliminary design of the chosen solution. To facilitate and assist in funding these tasks and
the final design and construction phases the following is recommended.
· DEP should seek additional funding for Connecticut under Section 319 Non-Point
Source Fund from the Clean Water Act.
· DEP should consider the possibility of modifying the Clean Water Fund program(s) to
include agricultural waste management projects. The Department could consider the
programs of other states, such as South Dakota, to explore how those programs have
· Lobby USDA for Rural Development funds for Connecticut to conduct feasibility
studies, develop business plans and preliminary designs for regional and individual farms
· DEP should seek Clean Water Fund increase for construction phases of manure
management facilities for regional facilities and individual farms.
· NRCS in Connecticut should seek additional EQIP Funding for Connecticut to address
farmers' needs with regional or individual farm modifications.
· CT DOAG should establish funding for the Environmental Assistance Program (EAP)
consistent with farmers' needs to meet the proposed CAFO regulations. Funding for four
regional composting facilities at a one facility per year rate and on the order of 10
individual farms per year for liquid/solid separation systems should be considered. The
estimated funds needed would be $2.7 million for the regional facility and $5.2 million
for 10 farms ($0.52 million per farm) for liquid/solid separation. The total fund
requirements would be a total of $7.9 million per year.
· Explore using existing funding mechanisms, such as EAP or USDA Rural Development,
to fund feasibility studies, business plans and preliminary designs of regional facilities
and individual farms solutions.
· Farmers should seek EQIP and EAP Funding to address modifications such as storage
facilities and liquid/solid separation needed on farms to meet proposed CAFO
requirements or participation in regional facilities.
· Use the NRCS Conservation Innovation Grant as a source of funding for Alternative
Technologies as site specific feasibility of these technologies is solidified.
· Groups interested in a regional manure facility should examine the applicability of EQIP
funding for a regional project in which participant farmers would apply individually for
support. They should also examine the applicability of the CT DOAG EAP funding for a
regional manure management project.
· Groups interested in a regional manure facility should review the availability of federal
funding under the USDA-NRCS Renewable Energy and Energy Efficiency Program.
Farmers who are considering undertaking energy efficiency or methane digester projects
can look to this fund for support. Further, they should examine this program in light of
its potential to support a regional digester project.
The above information comes from the Feasibility Study for Alternative Technologies and Utilization for Managing Dairy and Poultry Manure funded in part by the CT DEP through a US EPA Clean Water Act Section 319 nonpoint source grant. To access the full report click on the following link Feasibility Study for Alternative Technologies and Utilization for Managing Dairy and Poultry Manure.