ENVIRONMENTAL SERVICES Natural Resources and POLK COUNTY Drainage Division Board afCou.nty Commissioners 4177 Ben Durrance Road Bartow, FL 33830 (941) 534-7377 FAX (941) 534-7368 Lake Mariana Water Quality Improvement Project, Polk County, FL June 2000 Submitted to: Prepared by: The Charlotte Harbor National Estuary Program and The Southwest Florida·Regional Planning Council Polk County Natural Resources Division Polk County, Florida Printed on recycled paper Equal Opportunicl' Emplol'cr
43
Embed
Lake Mariana WaterQuality Improvement Project, PolkCounty ......Lake Mariana is a 204 hectare lake in north central Polk County, Florida. The lake is in the Winter Haven Ridge physiographic
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
ENVIRONMENTAL SERVICESDEPARTM~NT
Natural Resources and POLK COUNTYDrainage Division Board afCou.nty Commissioners
4177 Ben Durrance RoadBartow, FL 33830
(941) 534-7377FAX (941) 534-7368
Lake Mariana Water Quality Improvement Project,Polk County, FL
June 2000
Submitted to:
Prepared by:
The Charlotte Harbor National Estuary Programand
The Southwest Florida·Regional Planning Council
Polk County Natural Resources DivisionPolk County, Florida
Printed on recycled paper
Equal Opportunicl' Emplol'cr
1
"'..........~+moBC:J0()~-0(l,.
"'~
~
,"' ~
INTRODUCTION
The Lake Mariana Water Quality Improvement Study was a cooperative Early ActionDemonstration Project between the Charlotte Harbor National Estuary Program and Polk CountyNatural Resources. Additional funding for specialized chemistry analyses was made possible bythe Southwest Florida Water Management District (SWFWMD) and the Florida Department ofEnvironmental Protection (FDEP).
Lake Mariana is a 204 hectare lake in north central Polk County, Florida. The lake is in theWinter Haven Ridge physiographic region and within the Peace River drainage basin. It is part ofthe headwaters for the Winter Haven Chain ofLakes and ultimately, flows into the Peace Riverand travels south and west to Charlotte Harbor and the Gulf ofMexico. The watershed for LakeMariana is approximately 763 hectares and includes both the eastern portion of the City ofAuburndale and unincorporated Polk County north of US 92. Throughout the watershed the landuse has been extensively altered from it's native state and now includes the followingdesignations: single family residential, light-industrial and commercial, and including a commercialnursery. The south and western portion of the immediate watershed is not serviced by a centralsewer system and therefore the homes treat waste with on-site sewage treatment disposal systems(OSTDS). No point source discharges currently enter the lake, although there are severalwastewater treatment plants (packaged plants) within the area and seasonal overflow from one ofthe plant's settling pond has occurred in the recent past.
Water quality data has been collected since 1985 by the Polk County Natural Resources Divisionand which classifies the lake as mesotrophic and nutrient balanced. The lake's trophic state (TSI)has remained in the mid to upper fifties for the last fifteen years. The current TSI places it in thegood category (Friedman and Hand 1989), but with a small increase in the TSI the classificationwould change to fair (Fair 60-69). A Diagnostic Feasibility Study ofthe lake was prepared bySWFWMD that indicated water quality and habitat diversity was on the decline (SWFWMD1996). Over the last several years the lake has changed from a predominately aquatic macrophytehabitat to a phytoplankton lake with occasional algal blooms. The major influence for this changehas been anthropogenic. In the early 1990's, the removal ofaquatic macrophytes began, first toremove nuisance plants, i.e., hydrilla, and later a considerable amount of the desirable vegetationwas eradicated with the introduction ofgrass carp. The southern portion of the lake, which ispredominately residential, is practically denuded of macrophytes and as a result, shoreline erosionis substantial. Removal of the aquatic macrophytes has encouraged the introduction and increasedpopulations of algae.
The water quality study was designed to 1) identifY the source(s) ofnutrient loadings to the lakeand 2) to quantifY the loadings for nutrients from each source(s), ifpossible. Potential sourcesinvestigated were: stormwater runoff, atmospheric deposition, and OSTDS.
Central Florida has received below normal rainfall for the last sixteen consecutive months andwhich has negatively affected this investigation. The raw data are therefore based on abnormallylow seasonal rainfall, but loadings were projected and interpolated for the"typical"annual rainfall
3
solids, ammonium-nitrogen, TKN-nitrogen, NOx-nitrogen, ortho-phosphorus, total phosphorus,enterococcI oactena and specItIc conductIvity. For mass ioadings calculations, results reported asbelow the detection limit were transposed to one-half of the analytes' detection limit.
Polk County Laboratory chemistry methodology for sample analyses:
An Aerochemlm wet/dry atmospheric deposition sampler was located on county right of way nextto Lake Cannon, approximately 3 kilometers (km) south of the Lake Mariana watershed. LakeCannon was selected because it is located in the central region of the Winter Haven Chain ofLakes and deposition samples would provide a good representation of the nutrient loadings forthe local watershed. A American Sigma rain gage with sampler instrument processor head wasused to continuously monitor rainfall totals and duration. A solar panel provided the power for thedeposition sampler. Although the Aerochemlm collected both wet(rain) and dry deposition only thewet samples were sent to our laboratory for analyses. Dry deposition is still somewhatcontroversial for interpreting and typically not included in the final analysis (Dr. Garth Redfield,SFWMD, personal communication). Collections were made montWy and samples were analyzedfor total nitrogen and total phosphorus. Nutrient species could not identified and only grossloadings were calculated. Minimum levels of loadings were calculated and evaluated using thewet samples. Projected loadings for the mean annual rainfall were then interpolated from theempirical data.
The Aerochem was purchased with the SWFWMD SWIM funds and will remain at the presentsite collecting atmospheric deposition data indefinitely. Nutrient samples are continuing to becollected by our laboratory for future reporting.
Septic Tanl( Impacts
In the study area, the surficial groundwater is confined by a hard clay layer averaging 2.5- 3.0meters from the surface. Land use is predominately single family residence with modest homeson small lots. Many septic systems and drain fields were constructed within five to ten meters ofthe lake and/or drainage ditches that flow to the lake.
5
Lake arianaSu icial roundwater
Station Locations
a
7
e
,l!!
Cla.na
N
AC)Surficial Groundwater
Stations
This calculates to 2.1 kg ha-1 yr-1 and 0.22 kg ha-1 yr-1 of total N and Total P respectively.
A breakdown of the percent nitrogen species present in the loadings shows inorganic N as N02 +N03
, comprising 66 % of the total N. And organic or bound P as the dominant species, at 85 %.
Results for Station 23, which is the drainage from the light industriaVcommercial area was foundto have annual loadings of
Nutrient Loadings Dry Season Wet Season Total Yr-1
Total Nitrogen 2 kg 5.2 kg 7.2 kgTotal Phosphorus 0.74 kg 1.1 kg 1.84 kgOrtho/Reactive Phosphorus 0.47 kg 0.5 kg 0.97 kg
This calculates to 0.04 kg ha-1 yr-1 and 0.01 kg ha-1 yr-1 of total N and total P, respectively.
Nitrogen species was about evenly divided between organic and inorganic N. Total P loading wasdominated by organic or bound P at 64 %.
The various nutrients and their associated species, plus total suspended solids, were statisticallyevaluated with regression and correlation tables with no significant relationship between anycombination of variables at P > 0.050. Results should be viewed cautiously, as the past sixteenmonths of rainfall in the region has been at a record low and calculations were derived based on atypical year of normal rain events.
9
Total Nitrogen Loadings ISeasonalStormwater
350
300
250mE
200«SLm0)0 150........
n.'...~
100
50Site 21
0Dry Wet
Figure 2
Site 22
Dry Wet
Sites
11
Site 23
Dry Wet
Total Phosphorus Loading/SeasonalStormwater
35.-----------------------,Site 22
Site 23
Dry WetDry Wet
Site 21
Dry Wet
5
o -+---""'--"""'1"""----,---
25
30
10
oE ·20
~C)o 15............~
Figure 4
1'-'. .)
Figure 5
Nutrient Wet Depostion LoadingExtrapolated for normal annual rainfall
15
Phosphorus LoadingStormwater vs Wet Deposition
0+------
100 -r-----------------------,
80'fF'
Ba.."
>en 60
E«Ua.."C) 400-am.....
~20
Wet Deposition Stormwater Runoff
Figure 1
17
to return to normal and recharging of the wells is possible. Results will be available when this isCOmple[ea.
CONCLUSIONS
Atmospheric deposition wet loading calculations for nitrogen indicated direct atmosphericdeposition from rainfall accounted for approximately seven times the mass loading for all theother investigated sources combined. Although not as proportionally significant, wet depositionof phosphorus was 38 % greater than stormwater.
Nutrient loading to the lake from stormwater runoff was the most significant from the major ditchsystem that drains the City of Auburndale and the southwestern residential area ofLake Mariana.The other two land use areas studied have contributed nutrients to the lake but are very minorcompared to the urban/residential area.
OSTns runoffvia surficial water seepage was identified and may contribute both nutrients andpathogens to the immediate surface waters but further investigation is needed to order to quantifythe significance. Inorganic nitrogen and organic phosphorus are the major species of nutrientsthat are being transported to the lake. Cyanobacteria (blue-green algae) blooms have beenreported to be increasing over the last several years especially during the wet season. Algalblooms could be related to the availability of the nutrients following storm events.
19
APPENDIX
Summary of Positive Results Stormwater Monitoring atLake Mariana - Station #021 Drv Season Events
marcty2101
, Sample NO.1 IAdiusted •• , Sample NO.2 I Adjusted I Sample No. 31 Adiusted IBaseflow I Seasonal
I n?fn?'gQ 1 P ....<:<:.!H·c! -,~'?q!QQ 0Sfn71QO----- --------------.----- ------ -_.--- ----- ------- ---.-----------, ------r----r---------jSa!Tm!p fl~t9·
• Event mean concentration (EMC) is the average of adjusted pollutant concentrations for each of the qualifying storm events.•• The sample results are adjusted to account for base flow concentrations according to the following formula:Adjusted pollutant concentration = (Analytical Result) (Total Volume) - (Baseflow Concentration) (Baseflow Volume)
(Storm Volume Sampled)
Summary of Positive Results Stonnwater Monitoring atLake Mariana - Station #021 Wet Season Events
BDL (or <) =Below Detectable LimitsNT = Not TestedNfA = Not Applicable
* Event mean concentration (EMC) is the average of adjusted pollutant concentrations for each of the qualifying storm events.*" The sample results are adjusted to account for base flow concentrations according to the following fonnula:Adjusted pollutant concentration = (Analytical Result) (Total Volume) - (Baseflow Concentration) (Baseflow Volume)
(Stonn Volume Sampled)
Summary of Positive Results Stormwater Monitoring atLake Mariana - Station #022 Wet Season Events
marwet2.201
I Sample No. 1 I Adjusted ,,* I Sample NO.2 I Adjusted I Sample No.3 I Adiusted I Baseflow I SeasonalI Results I Sample 1 I Results I Sample 2 I Results I Samol", 3 I ! Fv.on+ l\/L':'l""l.T"!
Table II InorQanics: (uall)Arsenic:Cadmium:Chromium:Copper:Lead:Nickel:Selenium:Zinc:
_.
BOL (or <) = Below Detectable LimitsNT = Not TestedN/A =Not Applicable
"Event mean concentration (EMC) is the average of adjusted pollutant concentrations for each of the qualifying storm events.,'''' The sample results are adjusted to account for base flow concentrations according to the following formula:Adjusted pollutant concentration = (Analytical Result) (Total Volume) - (Baseflow Concentration) (Baseflow Volume)
(Storm Volume Sampled)
Summary of Positive Results Stonnwater Monitoring atLake Mariana - Station #022 Drv Season Events
man:lry2201
I Sample No.1 IAdiusted ~ I Sample NO.2 I Adiusted Sample No.3 Adiusted I Baseflow I SeasonalI Results ISample 1 I Results I Sample 2 Results Sample 3 I I Event Mean
Sample Date: .__._______LQ2I.9.J!§~ __L_.f~Elsults L 04/29/99 .. 1 05/07/99 I I I Conr:0!1fr.:::!tir)'f"l *
BDL (or <) = Below Detectable LimitsNT = Not TestedN/A = Not Applicable
• Event mean concentration (EMC) is the average of adjusted pollutant concentrations for each of the qualifying stonn events.•• The sample results are adjusted to account for base flow concentrationS according to the following formula:Adjusted pollutant concentration = (Analytical Result) (Total Volume) - (Baseflow Concentration) (Baseflow Volume)
(Storm Volume Sampled)
S'Jmmary of Positive Results Stormwater Monitoring atlake Mariana - Station #023 Wet Season Events
B. Composites: (mgll)Total Suspended Solids: 15.3 15.3 352 352 26.0 26.0 NT 25.88Total Kjeldahl Nitroaen (as N): 1.506 1.506 0.438 0.438 0.544 0.544 NT 0.640Total Nitrate-Nitrite (as N): 0.632 0.632 0.357 0.357 0.230 0230 NT 0.187Phosphorus, Ortho: 0.096 0.096 0.068 0.068 0.092 0.092 NT 0,079Phosphorus, Total: 0275 0.275 0.153 0.153 0.184 0.184 NT 0.181
Table II Inorganics: (ugfl)Arsenic:Cadmium:Chromium:Copper:Lead:Nickel:Selenium:Zinc:
BDL (or <) = Below Detectable LimitsNT = Not TestedN/A = Not Applicable
* Event mean concentration (EMC) is the average of adjusted pollutant concentrations for each of the quaflfying storm events.** The sample results are adjusted to account for base flow concentrations according to the following formula:Adjusted pollutant concentration = (Analytical Result) (Total Volume) - (Baseflow Concentration) (Baseflow Volumel
(Storm Volume Sampled)
Summary of Positive Results Stormwater Monitoring atLake Mariana - Station #023 Drv Season Events
mard-y2301
I Sample No.1 I Adjusted'" ISamole NO.2 I Adiusted I Sample NO.3 I Adjusted I Baseflow I SeasonalI Results I Sample 1 I Results I Samole2 I Results I Sample 3 I I Event Mean
~?"""'''''''C1 n'::ltp· ! n1 nAloa I O,-. ..... ~ .. l·l',;'" I o ").n')!(\'"" r, _-~ !~~ '0 ...... r.,.
B. Comoosites: (mQII)Total SusDended Solids: 7.6 7.6 30.4 30.4 33.2 33.2 NT 28.32Total Kieldahl Nitroaen (as N): 0.608 0.608 0.599 0.599 0.917 0.917 NT 0.683Total Nitrate-Nitrite (as N): 0.126 0.126 0.205 0.2 0.411 0.411 NT 0.173Phosphorus Orlho: 0.348 0.348 0.236 0.236 0.247 0.247 NT 0.200Phosphorus Total: 0.381 0.381 0.327 0.327 0.337 0.337 NT 0.315
Table If lnomanics: (ua!l)Arsenic:Cadmium:Chromium:Copper:Lead:Nickel:Selenium:Zinc: -
BDL (or <) = Below Detectable LimitsNT = Not TestedN/A = Not Applicable
* Event mean concentration (EMC) is the average of adjusted pollutant concentrations for each of the qualifying storm events.*" The sample results are adjusted to account for base flow concentrations according to the following formula:Adjusted pollutant concentration = (Analytical Result) (Total Volume) - (Baseflow Concentration) (Baseflow Volume)
(Storm Volume Sampled)
Atmospheric Deposition Data
REPORT OF ANALYSIS
POLK COUNTY NATURAL RESOURCES & DRAINAGE LABORATORY
\ __··.i ..... } -1-"; ,oJ I '",'
SITE INWOOD AEROCHEM DATE COLLECTED 02/18/99 RECEIVED 02/18/99
LAB # 11772 TIME SAMPLED 1500 GRP COMPLETED 02/25/99
SAMPLED BY MM LOC DESC AVE 0 BET. 31ST NW & 28TH NW, WH, FL
LAT 280220.9 LON 814543.06 STATION DEPTH SAMPLE DEPTH
ST/CO FIPS12105 STATION TYPE /AMBNT USGS HUC3100101
SAMPLE TYPECOMP S C: AD P C: 4 AGENCY CODE21FLPOLK*******************************~**~******************************************
THE LAKE MARIANA WATER QUALITY PROJECT AND THE DEVELOPMENT OF THESMOKING GUN MODEL FOR DETECTING HUMAN SEWAGE
C. Joe KingPolk County Natural Resources
Bartow Florida The Lake Mariana Water Quality Improvement Study was a cooperative Early Action DemonstrationProject between the Charlotte Harbor National Estuary Program and Polk County Natural Resources. Funding for specialized chemistry analyses was made possible by the Southwest Florida WaterManagement District SWIM program and the Florida Department of Environmental Protection.
Lake Mariana is a 204-hectare lake in north central Polk County. The lake is in the Winter HavenRidge physiographic region and the upper Peace River drainage basin. It is part of the headwaters forthe Winter Haven Chain of Lakes and ultimately, flows into the Peace River and travels south toCharlotte Harbor and the Gulf of Mexico. The watershed for Lake Mariana is approximately 763hectares and includes both the eastern portion of the City of Auburndale and unincorporated PolkCounty north of US 92. Throughout the watershed the land use has been extensively altered from itsnative state and now includes the following designations: single family residential, light industrial andcommercial, and including a commercial nursery. The southern and western portions of the immediatewatershed are not serviced by a central sewer system and therefore the homes treat sanitary wasteswith on-site sewage treatment disposal systems (OSTDS). No point source discharges currently enterthe lake, although there are several wastewater treatment plants (packaged plants) within the area andseasonal overflow from one of the plant’s settling pond has occurred in the recent past.
Water quality data has been collected since 1985 by the Polk County Natural Resources Division andthe lake is classified as mesotrophic and nutrient balanced. The lake’s trophic state (TSI) has remainedin the mid to upper fifties for the last fifteen years. The current TSI value is between the “good” and“fair” categories. Over the last several years the lake has changed from a predominately aquaticmacrophyte habitat to a phytoplankton lake with seasonal algal blooms. The major influence for thischange has been anthropogenic. In the early 1990's, the removal of aquatic macrophytes began, first toremove nuisance plants, i.e., hydrilla, and later a considerable amount of the desirable vegetation waseradicated with the introduction of grass carp. The southern portion of the lake, which is predominatelyresidential, is practically denuded of macrophytes and as a result, shoreline erosion is substantial. Removal of the aquatic macrophytes has encouraged the introduction and increased communities ofalgae and cyanobacteria.
The water quality study was designed to 1) identify the source(s) of nutrient loadings to the lake and 2)to quantify the loading of nutrients from each source(s). Sources investigated were: storm water runoff, atmospheric deposition, and OSTDS. Total nutrient loadings and yields were calculated.
An OSTDS model (“The Smoking Gun”) was additionally developed to identify nutrients andpathogens as contributing to the pollution impact of the lake. The model developed was qualitative andbased on the relative contribution of three metrics that are evidence for human fecal contamination. Themetrics were: 15/14nitrogen isotope ratios, enterococci bacteria, and caffeine. The hypothesis is, if all
three analytes are detected than human sewage is present. Human sewage can increase the loadings ofnutrient species that have the potential to negatively impact the surface water; but could also contributehuman pathogens that may produce health risks for users of the lake. Quantitative interpretation was notmade with this study, only a determination that human sewage may be present.
Nitrogen isotope samples were taken from drainage canals that were dry, except surficial groundwaterseepage, and downstream from OSTDS drainage fields. Results showed a 15/14nitrogen ratio of 11.7and 12.1. These are in the range to show organic nitrogen was present in the groundwater. TheUSEPA guideline for enterococci bacteria, which would indicate human health risk, is > 33 col/100mls. Enterococci bacterial concentrations at the five wells ranged from non detection to 324 col/100mls andall wells had the bacteria detected at least once. Enterococci were also detected in the drainage canalsand outfalls to the lake > 1000 col/100mls. The highest concentration, 8700 col/100mls, occurred in acanal within a very compact single family residential area with septic drain fields within several meters ofthe surface water. Enterococci bacteria do not typically live more than 48 hours in freshwater. Therefore, the source of the bacteria is local. Caffeine samples were collected, at all five wells beforethe lack of recharge to the wells made sampling impossible. Caffeine was detected in one well. Due tothe caffeine molecule being quickly broken down biochemically in the groundwater environment anydetection was significant.
Although results are preliminary, the Smoking Gun detected human sewage as present in surficialgroundwater. Both nutrients loading and potential human pathogens could be impacting the lake fromthe OSTDS. Polk County Natural Resources plans to continue with the OSTDS study whenconditions permit for the groundwater levels to return to normal and recharging of the wells is possible. Results will be available when this is completed.
Atmospheric deposition wet loading calculations for nitrogen suggested direct atmospheric depositionfrom rainfall accounted for the majority of the annual mass loading. Results were obtained during anunusually dry year and may not be representative. Further study is continuing and results will beavailable in early 2002. Although not as proportionally significant, wet deposition of phosphorus wasalso quantified and loadings were higher than the loadings from storm water runoff.
Nutrient loading to the lake from storm water runoff was most significant from the major ditch systemthat drains the City of Auburndale and the southwestern residential area of Lake Mariana.The other two land use areas studied have contributed nutrients to the lake but are very minorcompared with the urban/residential area.
All three sources studied contributed to nutrient loadings and maybe also be a source for humanpathogens. Inorganic nitrogen and organic phosphorus are the major species of nutrients that werebeing transported to the lake. Cyanobacteria (blue-green algae) blooms have been reported to beincreasing during the last several years, especially during the wet season. Algal blooms could be relatedto the availability of the nutrients accumulating from a combination of all sources, particularlyphosphorus. Many cyanobacteria present in the lake are nitrogen fixing species and are therefore moredependent on the phosphorus component of the loadings. This gives the cyanobacteria a competitiveedge and helps to explain their current dominance as a community. Further investigation is needed toquantify the significance of each source and to decide what management decisions should be made to
reduce the impacts that are continuing to favor the phytoplankton as the dominant community.