Approximately 2650 m~/day of secondarily-treated efflt~ent is currently discharged into a 206 ha mixed hardwood swamp located south of Jacksonville, Florida.In the early summer of 1981, a study was conducted to assess (i) whether the swamp was s~tisfactorlly assimilating the present discharge, and (2) whether the swamp ecosystem was suffering significant adverse impacts due to the discharge.Intensive field sampling coincided with a period of extended drought.The study plan included examination of water chemistry and vegetation at the receiving swamp and at four nearby control swamps not receiving scco:~dary effluent.The major outflow of the receiving swamp differed significantly from outflows of the control swamps in concentrations of total nitrogen, nitrate-nitrite nitrogen, total and dissolved phosphorus, and specific conductance.Based on flow measurements and mass balance c~lculations, the receiving swamp achieved nutrient "removal" rates of 87.0% (26.1 kq/day) for total nitrogen and 62.0% (8.8 kg/day] for total phosphorus.Data indicated that much of this removal occurred throuqh infiltration.Field investigations indicated that swamp vegetation stresses were present at the receiving swamp and at one of the control swamps.

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The authors have recently used several innovative sampling techniques for ground water monitoring at hazardous waste sites. Two of these techniques were used for the first time on the Biscayne Aquifer Super‐fund Project in Miami, Florida. This is the largest sampling program conducted so far under the U.S. Environmental Protection Agency (EPA) Superfund Program. One sampling technique involved the use of the new ISCO Model 2600 submersible portable well sampling pump. A compressed air source forces water from the well into the pump casing and then delivers it to the surface (through a pulsating action). This pump was used in wells that could not be sampled with surface lift devices. Another sampling technique involved the use of a Teflon manifold sampling device. The manifold is inserted into the top of the sampling bottle and a peristaltic pump creates a vacuum to draw the water sample from the well into the bottle. The major advantage of using this sampling technique for ground water monitoring at hazardous waste sites is the direct delivery of the water sample into the collection container. In this manner, the potential for contamination is reduced because, prior to delivery to the sample container, the sample contacts only the Teflon, which is well‐known for its inert properties. Quality assurance results from the Superfund project indicate that these sampling techniques are successful in reducing cross‐contamination between monitoring wells. Analysis of field blanks using organic‐free water in contact with these sampling devices did not show any concentration at or above the method detection limit for each priority pollutant.