Aerial view of the Warren, Maine lagoon system. Photo courtesy of Woodard and Curran.

Lagoon Systems In Maine 

Systems In Maine

An Informational Resource for
Operators of Lagoon Systems

Mars Hill Wastewater Lagoon System - Mars Hill  Maine. Photo Courtesy of Wright-Pierce Engineers.
 Mission  |  Search  |  Acknowledgements  | Discussion Group |  Contact Us  | Links

Design & Operation
Lagoon Aeration
Tech Papers
Operation Articles
Lagoons In Maine
The Laboratory
Maine Lagoon News
Lagoon Biology

2003 Maine Wastewater Salary Survey as conducted by the Maine Wastewater Control Association

2003 Maine Wastewater Rate Survey conducted by the Maine Rural Water Association

Maine DEP Monthly
O & M Newsletter

Maine and WEF's
Operation Forum

Penobscot Watershed and Development of a TMDL 

EPA Binational Toxics

Maine Rural Water

Maine Wastewater
Operator Certification

Maine Is Technology

Maine Wastewater Control Association

Maine WasteWater Control Association

Wastewater Engineering



Land Application of Biosolids

Aerated Lagoons

Land application is the application of biosolids to the land to either condition the soil or to fertilize crops or other vegetation grown in the soil. Nearly half the biosolids production in the United States is currently being used beneficially to improve soils. Over the past several years, the quality of municipal sludges has improved dramatically due in part to enforcement of federal, state and local regulations and in part to the pretreatment standards that indirect dischargers, such as industries, must comply with before they send their wastewater to public facilities for final treatment.

Historically, sewage sludge has been considered a waste and has been dumped in municipal and commercial land fills or the ocean - such practices were easy and cheap. But times have changed and so too, have our attitudes of sludge management. We have come to recognize, that like animal wastes, wastewater residuals are a part of the natural life cycle. They have nutrient and soil-enhancing properties that make them a practical choice for a variety of beneficial uses.

Traditionally, liquid or dewatered biosolids have been applied successfully to agricultural lands, forests, or reclaimed lands. More recently, there has been greater emphasis on such markets as landscaping projects, nurseries, sod farms, and direct use by homeowners.

aerated lagoons


    The notion of nourishing the land with human animal wastes is not new. For thousands of years farmers have recognized the value of human manure as a fertilizer. In fact, sewage sludge has been applied to the land in in the United States and Europe for over 40 years. Today, over half of the sewage sludge generated in the U.S. is land applied.

Biosolids contain many of the same constituents as commercial fertilizers, including invaluable organic matter, nitrogen and phosphorous. While not a complete replacement for chemical fertilizers in terms of nutrient ratios, biosolids do some things that chemical fertilizers can't do. They're composed of organic matter that promotes necessary bacterial activity and improves the structure, texture, and water retention characteristics of the soil. These properties stimulate the growth of vegetation, which helps reduce soil erosion and improve crop yields. Biosolids also provide trace metals and nutrients that commercial fertilizers do not have.

Biosolids are generally land applied using one of several techniques. The biosolids may be sprayed or spread on the soil surfaces and left on the surface. They may be tilled (incorporated) into the soil after being surface applied or injected directly below the surface for producing row crops or other vegetation and for establishing lawns.

Biosolids in a liquid state can be applied using tractors, tank wagons, irrigation systems, or special application vehicles. Dewatered biosolids are typically applied to land using similar equipment to that used for applying limestone, animal manure, or commercial fertilizer. Both liquid and dewatered biosolids are applied to land with or without subsequent incorporation into the soil.


    Because biosolids are typically treated before being land applied, their use poses a low degree of risk. Biosolids applied to the land must meet risk-based pollutant limits specified in EPA Part 503. Many of the 503 requirements are based on the extensive multimedia risk assessment during which EPA addressed 25 pollutants using 14 exposure pathways. The risk assessment process resulted in the establishment of the state of the art risk-based standards for controlling the use and disposal of biosolids. In general, research results and operating experience over the past 25 years have greatly expanded EPA's understanding of the risks and benefits of using or disposing of biosolids.

Operational standards to control disease causing organisms called pathogens and to reduce the attraction of vectors (e.g., flies, mosquitoes, and other potential disease-carrying organisms) to the biosolids must also be met. In addition there are general requirements, management practices, and frequency of monitoring, record keeping, and reporting requirements that must be met.


     Experience and science shows that as long as the process is managed carefully and wisely, land application of biosolids can be effective, inexpensive, and "low tech" recycling option that benefits both generators and users. Consideration for land application sites may include depth to grounder, distance to surface water, slope, soil characteristics, distance to drinking water supplies, and proximity to homes, schools and other establishments. Agricultural lands, forest reclaimed lands, and public works projects are the most practical domains for land application uses.

AGRICULTURAL LANDS - Agricultural use accounts for approximately 77 percent of the biosolids that are land applied in the United States. This includes land that is used to grow both food crops and feed crops and pasture land. As with commercial fertilizers, farmers must follow best management practices when applying biosolids. The material must be applied at the correct agronomic rate for the plant being grown and must be monitored. Biosolids may need to be supplemented with other fertilizers to balance crop needs.

FORESTS - Biosolids are used in civil culture to increase forest productivity for certain tree species. The application of biosolids to forest land can shorten pulp wood and lumber production cycles, especially on marginally productive soils.

LAND RECLAMATION SITES - Biosolids are used to help reclaim barren lands such as mines, quarries, gravel pits, and construction sites. Biosolids provide nutrients and condition the soil so that vegetation can be established. Vegetation reduces soil erosion and helps make the land productive again.

RECREATION AND OTHER USES - Biosolids are applied to areas of land to condition the soil and enhance the growth of vegetation. Example of such sites include parks, ball fields, golf courses, cemeteries, plant nurseries, and highway media strips.


Top of Maine Wastewater Lagoon systems

  Copyright 2003 |  Home | Site Map                                          

Search  |  Contact Us  | Links