In this section
Bugg Spring aerial view
Bugg Spring is a second-magnitude spring with a deep, circular pool about 400 feet in diameter. Except on the western side, the side walls are almost vertical, reaching depths of 170 feet to 175 feet. There is no boil observed on the pool surface due to the depth of the spring opening. There is very little aquatic vegetation, but algae are present in the spring pool and run. The spring run flows north about 0.8 mile into the Helena Run outflow from Lake Denham. The low-lying areas around the spring are densely forested, with sandhills to the south.
Bugg Spring pool
photo by T. Scott, FGS
Discharge at Bugg Spring was measured sporadically from 1943 to 1985. Seven discharge measurements by the U.S. Geological Survey (USGS) during this time period ranged from 17.66 cubic feet per second (cfs) in 1943, decreasing to 8.68 cfs in 1985 (the early data are not included in the Blue Spring Discharge Graph). From 1990 to the present, discharge has been measured by the landowner at least monthly, with more frequent measurements at times. The difference between the minimum and maximum discharges is 16.00 cfs. The maximum measured discharge of 19.80 cfs occurred in July 1991; the minimum discharge of 3.80 cfs occurred in January 1992. The mean and median discharges for the period from 1943 to 2010 are 11.25 cfs and 11.30 cfs, respectively (see the table below).
Bugg Spring was sampled seven times by USGS from 1967 to 1999. St. Johns River Water Management District sampled the spring three times in 1991 and has sampled it at least two to four times per year since 1997. The district currently samples Bugg Spring four times per year. Summary statistics of the water quality data for selected variables are shown in the table below.
Summary statistics of water quality and discharge at Bugg Spring
|Alkalinity, total, mg/L as CaCO3||106.0||127.0||126.0||144.0||59||1967−2010|
|Calcium, total, mg/L as Ca||45.0||50.7||50.8||59.0||42||2000−2010|
|Chloride, total, mg/L as Cl||6.0||12.6||13.0||20.1||57||1967−2010|
|Fluoride, total, mg/L as F||0.06||0.06||0.06||0.07||4||2001−2002|
|Magnesium, total, mg/L as Mg||3.0||3.3||3.3||4.5||39||2000−2010|
|Nitrate + nitrite, total, mg/L as N||0.11||0.47||0.46||0.71||54||1985−2010|
|Orthophosphate, total, mg/L as P||0.02||0.07||0.07||0.10||43||1972−2010|
|Phosphorus, total, mg/L as P||0.06||0.09||0.09||0.16||52||1972−2010|
|Potassium, total, mg/L as K||0.9||1.2||1.2||2.1||39||2001−2010|
|Sodium, total, mg/L as Na||4.6||8.0||8.0||11.0||42||2000−2010|
|Specific conductance, field, µmhos/cm at 25°C||227||287||292||334||54||1991−2010|
|Specific conductance, lab, µmhos/cm at 25°C||255||304||305||373||34||1967−2010|
|Sulfate, total, mg/L as SO4||0.6||8.1||8.8||11.0||55||1967−2010|
|Total dissolved solids, mg/L||110||170||172||240||46||1967−2010|
|Water temperature, °C||20.4||23.6||23.4||26.9||63||1967−2010|
mg/L = milligrams per liter
cfs = cubic feet per second
Age of discharge water
The age of water discharging from Bugg Spring was determined by measuring the concentration of carbon-14 and carbon-13 in the spring discharge, as measured in April 2001. Bugg Spring had a carbon-14 concentration of 42% modern carbon and a delta carbon-13 value of −9.95 parts per thousand. Fontes and Garnier (1979) interpreted carbon-14 age of Bugg Spring discharge at less than 50 years.