What agricultural land use occurs in the watershed?
The types of agricultural activities and facilities to identify and investigate include, but are not limited to, livestock farms (e.g., dairy, beef, chicken, deer, buffalo, horse, fowl), Concentrated Animal Feeding Operations (CAFOs), composting facilities, fruit and vegetable horticulture, manure spreading, horse farms, zoos, and kennels.
Record details such as whether there is a direct or indirect pathway to a water body, the type and number of animals, setback distance of fencing to a water body, manure management, runoff potential (including pollution source distance to water body, slope of the land), and any other observations relevant to water quality.
Livestock can be a major source of ground and surface water contamination by pathogenic bacteria. Addition- ally, the spread and application of animal manure can be a major bacterial transport pathway.66 Certain types of activities, such as CAFOs, may pose environmental and public health risks by increasing the amount of waste and contaminants produced.67
Pollutants from agricultural operations may reach sur- face waters through animal contact with water, improper manure management, runoff during wet weather events, etc. Studies have demonstrated that manure application can contribute significant amounts of bacteria to down- stream waters, especially following rainfall events that oc- cur soon after the manure is applied.68 Manure can harbor and release bacteria for weeks after it is produced.69
Conducting the Sanitary Survey
Discharges of manure from any type of livestock are initially under the jurisdiction of the Maine Department of Agriculture and must be reported to that agency. They should also be reported to the DEP to ensure that any water quality impacts from the ma- nure are eliminated. Additional bacterial samples can be collected to determine the impact of runoff from agricul- tural and other commercial operations.
The potential for agricultural activities to cause or contribute to impaired water quality reinforces the need to implement Best Management Practices (BMPs) such as the use of vegetative buffer filters, fencing to restrict animal access to water, rotational grazing, animal waste control facilities, pasture management, etc.22, 70
THINGS AREN’T ALWAYS AS THEY SEEM
The bacterial pathway may not be obvious. As a case in point: a small brook adjacent to a popular beach area had consistently elevated bacteria levels. Several attempts to identify the source(s) led to the discovery of a small discharge behind a pile of rocks on the bank of the brook. This discharge came from the neighbor- ing restaurant’s lobster pound tank. The discharge was tested for fecal indicator bacteria to verify that it was indeed contributing high bacteria levels into the brook.The local code enforcement officer worked with the restaurant owner to improve the condition of the tank and to filter the water entering and leaving this commercial operation. This less-than-obvious pollu- tion source was addressed and water quality on the beach improved.
Other types of activities and facilities to identify and record include but are not limited to:
Lobster pound tanks, aquaculture, and other