PTO vs Engine-Driven Manure Pumps: How to Size One
For most farms running their own manure with existing tractors in the 200 to 300+ horsepower range, Hoover Ag’s PTO pump covers the job.
Pennsylvania generates roughly 2.2 million tons of wastewater solids annually. That’s nearly a quarter ton per household statewide. Some of that material is landfilled, some is incinerated, and a significant share is treated to biosolids standards and land-applied as a soil amendment on farmland.
For farms that accept biosolids, the material is a source of nitrogen, phosphorus, organic matter, and other nutrients. For municipalities and treatment plants, land application is often the most economical and beneficial disposition route. For custom applicators, biosolids application is a distinct line of business with its own equipment, permitting, and operational patterns.
Here’s how the process actually works, and what equipment does the job.
Biosolids land application follows a chain of custody and compliance that starts at the wastewater treatment plant and ends at the field.
Treatment and classification. The generator (usually a municipal wastewater treatment plant) treats sewage sludge to meet Class A or Class B pathogen and pollutant standards. The material is tested and classified before it can be land-applied. Class B is the more common category for agricultural land application. Class A can be applied more broadly, including to public spaces.
Permitting. The generator holds the permit for land application through PA DEP. Individual permits or general permits (PAG-07 and PAG-08 are the general permit categories) cover the application activity. The permit specifies what can be applied, at what rates, and under what conditions.
Site identification and evaluation. Before biosolids can be applied at a specific site, the site has to be identified and evaluated for suitability. PA DEP’s regional biosolids coordinator evaluates the site.
Public notification. The generator must notify adjacent landowners, PA DEP, and the appropriate county conservation district at least 30 days before the first application at a site. PA DEP publishes notice in the Pennsylvania Bulletin and notifies the local municipality. After the 30-day period, land application can begin.
Application. The material is transported to the field and applied under the terms of the permit. Custom applicators typically handle this step.
Record-keeping. Application quantities, locations, and conditions are recorded and reported to PA DEP annually.
The whole chain runs through PA DEP’s Biosolids Program, and any farm hosting land application is part of a permitted operation, not an independent activity.
Biosolids can be applied with several equipment categories depending on the material’s form and the site conditions.
Dragline systems. For liquid or semi-liquid biosolids (which includes most Class B material), dragline systems are the most efficient application method. A pump moves biosolids through mainline hose to a hose reel at the field edge, and a drag hose feeds the application implement. Continuous flow, no tanker traffic on the field, high throughput.
Injection toolbars. Dragline injectors are the standard implement for biosolids where the plan and site conditions allow. Placing biosolids below the soil surface reduces odor sharply, cuts runoff risk, preserves more of the nutrient value, and shortens the site restrictions that come with Class B application.
Dribble bars. Dribble bar surface application is used when injection isn’t practical (fragile soils, established crops, specific field conditions). It’s a step up from splash-plate surface application in terms of odor and volatilization but keeps the material at the surface.
Tanker spreaders. For smaller volumes, isolated sites, or dry biosolids, tanker application still has a place. It’s operationally simpler than a dragline setup but slower per acre and harder on soils because of the vehicle weight on the field.
Solid spreaders. For dewatered or composted biosolids (Class A products in particular), conventional solid spreader equipment applies the material like a solid manure.
Most custom applicators running biosolids for a treatment plant own both dragline and tanker capacity so they can match equipment to the site.
Biosolids application draws more scrutiny than manure application, both from regulators and from the public. Odor complaints, runoff concerns, and public perception all matter more when the material has “sewage” in its history.
Injection addresses most of the concerns that make biosolids application controversial.
Odor drops sharply when the material goes below the surface instead of sitting on top of it. This matters most in areas with non-farm neighbors and matters for the applicator’s ability to keep working sites.
Runoff risk drops because the material is in contact with soil rather than exposed to rainfall. This matters for compliance and for water quality outcomes.
Nutrient preservation improves. Ammonia volatilization is a significant nitrogen loss route for surface-applied biosolids. Injection cuts that loss meaningfully.
Site restriction periods are shorter or more manageable. Class B biosolids come with harvesting and grazing restrictions post-application because pathogens are reduced but not eliminated. Injection with soil contact accelerates pathogen die-off compared to surface exposure.
For custom applicators building a business around biosolids, low-disturbance injection equipment is increasingly the default rather than the specialty option. Farms hosting biosolids application increasingly ask for injection specifically.
Class B biosolids are typically applied to non-food crops or to food crops with waiting periods before harvest. Common receiving crops include corn, hay, small grains, and pasture grass with harvesting restrictions. Class A EQ biosolids have fewer crop restrictions because pathogens have been reduced to non-detectable levels. Specific permits and plans dictate what applies at each site.
For farms considering biosolids as a nutrient source and for applicators planning field operations, several practical factors shape the work.
Setbacks and site conditions. Biosolids application has the same kinds of setbacks as manure application (streams, wells, occupied dwellings), often with additional requirements specific to the permit. Sites are evaluated in advance.
Application rates. Rates are governed by the site’s agronomic need, cumulative pollutant loading limits, and the terms of the permit. You can’t just apply biosolids at whatever rate you want.
Timing. Biosolids application has seasonal restrictions similar to manure. Winter application is generally avoided or heavily restricted. Application windows tighten in the Chesapeake Bay watershed.
Storage. If biosolids are staged on the farm before application, storage has to meet the standards in the permit. Uncovered staging near water or on slopes is not acceptable.
Field conditions. Wet or frozen ground shifts what equipment can work, same as with manure. A dragline with an injector can work fields that a tanker fleet can’t get onto, which is one of the reasons dragline is preferred at scale.
Most biosolids application in Pennsylvania is done by custom applicators contracted by the generator (the treatment plant). The economics favor this model because a specialized applicator can serve multiple treatment plants and spread the equipment investment across enough acres to make it work.
For farms, this usually means hosting a custom applicator on your fields rather than operating the equipment yourself. The applicator handles the equipment, the operations, and much of the compliance paperwork. The farm hosts the application, benefits from the nutrients, and is part of the permitted site.
Larger farms that already run their own dragline equipment for manure sometimes take on biosolids application directly, particularly if they have a long-standing relationship with a nearby generator. In those cases, the farm operates as (or contracts as) an applicator under the generator’s permit.
For applicators building out biosolids application capacity, the Hoover Ag lineup covers the injection and dragline application end. The dragline injectors come in configurations for grassland and row crop application. The 50 foot dribble bar handles surface application when injection isn’t the fit. The PTO pump and hose reels round out the dragline system.
The full manure equipment lineup is designed around dragline liquid application, and biosolids application uses the same core equipment as liquid manure application. If you’re spec’ing a system for biosolids work or expanding existing capacity, call (610) 468-9666 or get in touch.
Sources cited in this guide:
For most farms running their own manure with existing tractors in the 200 to 300+ horsepower range, Hoover Ag’s PTO pump covers the job.
If you haul or broker manure commercially in Pennsylvania, you need a certification, you need to maintain it with continuing education, and you need to keep records that prove you’re doing the work within the rules.
Biosolids are the nutrient-rich organic material produced when wastewater treatment plants treat sewage sludge to meet federal and state standards for beneficial use.