Groundwater Quality Impact by Chicken Farm Hen Dung in Salinas, Puerto Rico

EPA Grant Number: U915993
Title: Groundwater Quality Impact by Chicken Farm Hen Dung in Salinas, Puerto Rico
Investigators: Roubert, Mayra L.
Institution: University of Puerto Rico - Rio Piedras Campus
EPA Project Officer: Graham, Karen
Project Period: January 1, 2001 through January 1, 2004
Project Amount: $62,574
RFA: Minority Academic Institutions (MAI) Fellowships for Graduate Environmental Study (2001) RFA Text |  Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Academic Fellowships , Fellowship - Environmental Science


The objective of this research project is to identify statistical differences between nitrate concentrations in soil and water samples. In the last 70 years, Puerto Rico has experienced an evident economic development. Our agricultural economy, sustained mainly by sugar cane crops, changed to an industrialized one exerting a great pressure of development of the coastal areas.

Corn, mangos, papaya, bananas, and other plantation fruits in the town of Salinas take advantage of their well-known soil fertility. In addition to all these plantations, the development of the chicken farming industry also has been developed in the watershed. This activity requires less government regulation and for that reason people buy land for chicken farm construction without having proper management of their solid wastes.

Sampling wells from the Salinas-Guayama watershed have reflected very high nitrate concentrations, of the order of 80 mg/L. This nutrient concentration increases towards the north of the hydrographic river basin. Geocodified data using geographic information systems technology suggest that a chicken farm cluster located in the Húcar sector could be the cause of these high concentrations due to poor manure management. This situation could be a potential community public health risk, because the U.S. Environmental Protection Agency stipulates that for this purpose, the allowed maximum level should be 10 mg/L.

The nitrates act by releasing nitric oxide, which activates certain cycles in the cardiovascular system causing vasodilatation, blood platelets inhibition of aggregation, adhesion of leukocytes, and cellular proliferation. Babies smaller than 6 months who drink water containing large amounts of nitrate could become seriously ill or could even die if they are not treated in time. Some of the common symptoms are respiratory difficulties and blue baby syndrome (cyanotic). Other studies associate high nitrate levels with cancer development. Also, manure natural combustion could pollute air with bad odors, fugitive dust, and other resulting gases of the decomposition processes. These deposits attract flies and insects that as vectors increase the public health risk.


This research project involved collection of soil and underground water samples from the El Húcar area versus two other areas to relate nitrate concentrations in water with soil and chicken manure management. One hundred and forty-five soil samples from chicken farms had higher nitrate concentration than the control areas located in the upper and down side from the watershed. These levels are from 8.0 mg/L near septic tank areas to 266.00 mg/L near chicken bedding structures. The two other areas, the recreational and agricultural ones, had reflected very similar levels between them, on the order of 4.0 mg/L to 10.0 mg/L.

Supplemental Keywords:

fellowship, groundwater quality, nitrate concentration, Salinas, Puerto Rico, manure combustion, chicken manure, chicken farming.

Progress and Final Reports:

  • 2001
  • 2002
  • Final