U.S. ENVIRONMENTAL PROTECTION AGENCY WATER QUALITY" OF THE POTOMAC ESTUARI DISSOLVED OXYGEN BUDGET STUDIES 1970 DATA REPORT Number 26 MIDDLE ATLANTIC REGION-III 6th and Walnut Streets, Philadelphia, Pennsylvania 19106 ------- 903R70121 WATER QUALITY OF THE POTCMAC ESTUARY DISSOLVED OXYGEN BUDGET STUDIES 1970 DATA REPORT Number 26 U.S. EPA Region III tlsgional Center for Environmental 1'iibi'inaticn J.G50 Arch Street (3PM52) Philadelphia. PA 10103 Annapolis Field Office Region III Environmental Protection Agency ------- Annapolis Field Office Region III Environmental Protection Agency 1970 Data Report Number 26 WATER QUALITY" OF THE POTOMAC ESTUARY DISSOLVED OXYGEN BUDGET STUDIES Staff: James W. Marks, Chief, Analytical Laboratory Section Orterio Villa, Jr., Chief, Development Laboratory Section Anna R. Favorite, Statistician Evelyn P. McPherson, Technician ------- TABLE OF CONTENTS Page I INTRODUCTION 1 II STATION LOCATIONS 7 III SURVEY RESULTS 9 IV MAP appendix i ------- I INTRODUCTION A. Purpose and Scope Two dissolved oxygen budget studies were conducted by the Annapolis Field Office, Region III, Environmental Protection Agency during the weeks June 22-26 and July 20-21;. The pur- pose of these surveys was to further define the role of phy- toplankton in the DO budget of the upper Potomac estuary. B. General Remarks Transect and embayment samples were taken on three sta- tions, Broad Creek, Piscataway Creek and Gunston Cove. Loca- tion designations on survey results are as follows: RSM/RCM- right shore Maryland/right channel Maryland; LSV/LCV-left shore Virginia/left channel Virginia; El, E2, E3-embayment at headwaters, mid creek and mouth. C. Sampling Procedures Samples were obtained using a small submersible pump at- tached to a wire cable calibrated in feet. The pump was low- ered to the desired depth and allowed to run for two minutes before receiving in plastic containers. Dissolved oxygen (DO) samples were obtained directly from the pump outlet extending to the bottom of a conventional 300 ml DO bottle. The sample was allowed to overflow the bottle several times. The regular DO was fixed immediately. A DO in light bottle and a DO in dark bottle were placed in stream water for a four-hour in- ------- 2 cubation period, and fixed upon removal from river. Samples were stored on ice and analyses started upon return to the laboratory. Determinations of free, dissolved CO2 were car- ried out in the field by the Annapolis Field Office. D. Measured Parameters and Analytical Methods 1. Water temperature was determined using a mercury thermometer inserted into the sample container immediately upon collection. 2. Light extinction, in inches, was read with a 12" (30 cm) white secchi disk. 3. The pH measurements were made with a field pH meter. Ij. Total Phosphorus Reference: Menzel, D.W. and Corwin, N., 196£. The Measurement of Total Phosphorus in Seawater Based on the Lib- eration of Organically Bound Fractions by Persulfate Oxida- tion. Limonology and Oceanography, 10; 280-282. Murphy, J. and Riley, J.P., 1962. A Modified Single Solution Method for the Determination of Phosphate in Natural Waters. Analytica Chimica Acta, 27: 31-36. Total Phosphorus was determined after persulfate oxidation of the sample in an autoclave at 15 psi for 30 minutes. The resultant ortho-phosphate was then determined colorimetrically as the molybdenum-blue complex with the op- tical density measured at 882 my.. ------- 3 5. Inorganic Phosphorus Reference: Murphy, J. and Riley, J.P., 1962. A Modified Single Solution Method for the Determination of Phos- phate in Natural Waters. Analytica Chimica Acta, 27: 31-36. Inorganic Phosphorus was determined by automation of the above procedure using the Technicon "Auto Analyzer." The molybdenum-blue complex formed was determined colorimet- rically with the optical density measured at 885 my.. 6. Total Kjeldahl Nitrogen Reference: Standard Methods for the Examination of Water and Wastewater, 12 ed., 1965. Total Kjeldahl Nitrogen includes ammonia and organ- ic nitrogen and was determined by the standard micro-kjeldahl procedure. The sample was digested in the presence of strong acid to convert the organic nitrogen to ammonia. The ammonia was then distilled, collected in boric acid solution, nessler- ized and determined colorimetrically. 7. Nitrate + Nitrite Reference: A Practical Handbook of Sea Water Anal- ysis, J.D.H. Strickland and T.R. Parsons, Bulletin 167, Fish- eries Research Board of Canada, Ottawa, Canada, 1968. Nitrate plus nitrite nitrogen was determined by automation of the above procedure using the Technicon "Auto Analyzer." This procedure utilizes cadmium reduction of ------- u nitrate to nitrite and subsequent diazotization with sulfan- ilamide and N-(l-naphthyl)-ethylenediamine dihydrochloride with the optical density measured at 5^0 m)i.. The results were reported as nitrogen. 8. Ammonia Reference: Southeast Water Laboratory, FWQA, Methodology for the colorimetric determination of ammonia by the phenol-hypochlorite reaction. FWPCA Methods for Chemical Analysis of Water and Wastes, November 1969. Ammonia nitrogen was determined by automation of the phenol-hypochlorite procedure as described in the South- east Water Laboratory Methodology and later adopted as the official FWPCA procedure. The intensity of the indophenol blue color, formed by the reaction of ammonia with alkaline phenol-hypochlorite, was increased using sodium nitroprusside as an intensifying agent. The optical density was measured at 630 mjj. and calculated as NH^-N. 9. Total Organic Carbon Reference: Beckman Instruments, Bulletin 1|05>9. FWPCA Methods for Chemical Analysis of Water and Wastes, November 1969. Total Organic Carbon was determined with a Dow- Beckman Carbonaceous Analyzer after the sample had been purged ------- 5 with nitrogen gas for five minutes. 10. Chlorophyll a Reference: A Practical Handbook of Sea Water Anal- ysis, J.D.H. Strickland and T.R. Parsons, Bulletin 167, Fish- eries Research Board of Canada, Ottawa, Canada. 1968. Chlorophyll a was determined by extraction of mil- lipore filtered samples in 90$ acetone and read spectrophoto- metry ally. 11. Dissolved Oxygen Reference: Standard Methods for the Examination of Water and Wastewater, 12 ed., 1965. FWPCA Methods for Chemical Analysis of Water and Wastes, November 1969. Dissolved Oxygen was determined by the azide modi- fication of the basic Winkler method with the titration done potentiometrically with a Fisher automatic "titralyzer." 12. Biochemical Oxygen Demand Reference: Standard Methods for the Examination of Water and Wastewater, 12 ed., 1965. The Biochemical Oxygen Demand was determined by the azide modification of the basic Winkler method with the titra- tion done potentiometrically with a Fisher automatic "titraly- zer." The samples as received were diluted if necessary and transferred to standard 300 ml BOD bottles in triplicate. One ------- 6 initial DO and two final DO determinations were used through- out. Incubation was started immediately at 20 8C and continued for five days after which they were titrated. 13. Free Carbon Dioxide Reference: Standard Methods for the Examination of Water and Wastewater, 12 ed., 1965, pp. 77-85. Free carbon dioxide was determined in the field by a titrimetric procedure. Carbon dioxide reacts with sodium carbonate to form sodium bicarbonate. Reaction completion is indicated by development of a pink color characteristic of phenolphthalein indicator. ------- II STATION LOCATIONS Station Location 2 llith Street Bridge 3 Haines Point k Bellevue 5 Woodrow Wilson Bridge 6 El Broad Creek E2 E3 RSM RCM M LCV LSV 7 El Piscataway Creek E2 E3 RSM RCM M LCV LSV ------- 8 Station Location 8 Dogue Creek 8A El Guns ton Cove E2 E3 RSM RCM M LCV LSV 9 Hallowing Point 10 Indian Head 10A Occoquan Bay 11 Possum Point 12 Sandy Point 13 Smith Point Ik Maryland Point l£ Nanjemoy Creek 16 Route 301 Bridge ------- Ill SURVEY RESULTS 1970 POTOMAC ESTUARY DISSOLVED OXYGEN BUDGET SURVEY ANNAPOLIS FIELD OFFICE Sample Number Date Sample Taken Time Sample Taken Sample Loca- tion Sajnple Depth Feet Secchi Disk Inches Field pH Water Temp °C Total P0J. mg/1 P Inorganic P POlj mg/1 NO2+NO3 TKN mg/1 mg/1 N NO3-N NH3 mg/1 N TOC mg/1 Chloro- phyll a M-g/1 BOD mg/1 DO mg/1 DO Light mg/1 K) Dark mg/1 Incu- bation CQ time-out Ufj Station 2 - ll*th Street Bridge 70062301 6-23 0308 MC Surface 8.51 25 • 591* .109 .1*75 .200 8.31* 139.5 7.91* 1.0 02 MC 10 7.95 21*.5 .609 • 125 .500 .200 9.12 151.5 7.73 3.8 21*01 6-21* 0305 HC Surface 7.51 .1*81* .128 .711 .110 81*. 8 7.71* 5.1 02 MC 10 7.50 • 572 .122 .716 .11*0 90.0 7.86 It.l 072201 7-22 0928 MC Surface 9 25.5 .736 .271 .713 .1*69 .337 7.39 138.8 1*. 59 6.11* 11.29 5.92 1330 02 0930 MC is 25 .509 .295 .037 .1*86 .1*30 6.38 11*6.3 5.06 6.15 10.71 5.69 1330 Station 3 - Haines Point 70062303 6-23 0255 MC Surface 8.30 25.5 .182 .115 .1*65 .210 8.93 120.0 8.11 l*.lt ol* MC 10 7.90 25 .1*18 .118 .1*80 .225 6.81* 121*.5 8.02 6.6 21*03 6-21* 0255 MC Surface 7.35 .1*93 .125 .712 .150 90.0 8.03 5.1* 01+ MC 10 7.20 .696 .11*6 .72 5 .160 90.0 7.52 5.0 072203 7-22 091*5 MC Surface 9 26 .51*3 .256 . 81*0 .602 .061* 5.29 93.8 1*.68 5.55 9.1*7 It.ltO 11*00 01; MC 15 26 1.075 -1*52 .611 .067 7.30 99.0 7.39 5.28 8.78 It. 99 11*00 Station 1* - Bellevue 70062305 6-23 02^14 MC Surface 7.65 26 1.290 .512 .555 .500 7.39 101.3 6.62 8.1* 06 MC 20 7.60 25.5 1.51*8 • 530 .590 .525 13.96 123.0 6.23 7.1 0621*05 6-21* 02 bo MC Surface 7.50 26 1.1*86 .1*61* .1*75 .600 103.5 7.98 5.1* 06 MC 20 7.50 26 1.31*3 .360 .1*87 .290 129-0 7.87 5.2 072205 7-22 0955 MC Surface 9 25.5 1.302 .805 .777 .062 5.81* 1*6.5 6.72 1*. 35 8.06 3.68 151*5 06 MC 20 25.5 1.528 1.120 1.856 .780 .625 6.71* 39.8 7.90 l*.oo 6.87 3.29 15U5 Station 5 - Woodrow Wilson Bridge 70062307 6-23 0238 MC Surface 7.20 26.5 1. 7$1* 1.055 .620 .620 6.81* 116.3 6.27 9.2 08 MC 25 7.50 25.5 3.11*0 1.610 .600 .973 7.81* 108.8 5.55 12.0 21*07 6-21* 0225 MC Surface 7.30 26.5 1.508 • 550 .502 .610 106.5 6.69 7.2 08 MC 25 7.1*0 26 1.761 .601* • 503 .620 120.0 6.20 8.1* 072207 7-22 1018 MC Surface 10 25-5 1.358 -955 .796 .888 6.03 35.3 5.28 3.31 6.76 3-15 151*5 08 MC 25 26 1.528 .965 2.191 .787 1.058 6.97 1*6.5 6.38 3-61 6.10 2.96 151*5 Station 6 - Broad Creek 70062201 6-22 1350 El 2 10 8.20 27 96.0 10.97 9.1t9 7.0 02 1357 E2 2 11 8.30 26.5 lll*.0 10.1*3 8.2 03 1U05 E3 2 11 7.1*0 27 76.5 1* • 69 5.U0 It-1*7 13.2 01* 11*08 RSM 2 10 7.1*0 26 52.5 l*.8l 12.0 05 lias RCM 2 13 7.50 26.5 1*8.8 I4.81 5.36 -1+-3l+ 13.8 06 11*12 RCM 10 7.50 26 61.5 1*.52 13.2 07 11*35 M 2 12 7.60 1*1.3 1*.5B 5-14-7 1*.17 10.8 08 11*30 M 15 7.50 63.8 It. 25 13.0 09 11*25 M 30 7.50 26 95.3 l*.l6 It-89 3.1*0 16.2 10 lUWi LCV 2 11 7-50 26.5 52.5 1*. 10 12.1* 11 lhho LCV 10 7.1*0 26 61*.5 U. 31 12.0 12 il*5o LSV 2 10 7.70 27 101*. 3 6.57 5.52 13.2 ------- Date Sample Sample Wumber Taken lime Sample Taken Sample Loca- tion Sample Depth Feet Secchi Disk Inches Field PH Water Temp SC Total P PO; mg. Inorganic P P0U mg/1 n02+N03 TKN mg/1 mg/1 H HO^-H Station 6 - Broad Creek -Continued .2309 6-23 El 2 8.20 25 1.121 .310 1.991* .1*80 10 0206 E2 2 26 1.121 .51*3 .51*0 11 0159 E3 2 7.60 26 1.637 .960 2.103 .1*50 12 015U RSM 2 26 1.750 .935 .500 13 oiaa RCM 2 7.50 26 1.559 .955 2.568 .510 llj RCM 10 26 1.626 .950 .525 15 0132 M 2 7.50 26 1.511* .995 2.1*71 .530 16 M 15 26 1.772 .970 .535 17 MC 30 7.1*0 25.5 1.907 .980 2.31*9 .530 18 0125 LCV 2 25.5 2.209 .81*5 .1*85 19 LCV 10 25-5 2.019 .960 .I480 20 0115 LSV 2 7.52 25.5 1.963 1.125 2.91*9 .1*85 55 1322 El 2 12 7.70 27.5 56 1330 E2 2 12 27 57 1337 E3 2 11 8.10 26.5 58 13U1 RSM 2 13 26.5 59 13U5 RCM 2 16 8.00 27.5 60 13U2 RCM 10 26.5 61 1100 MC 2 12 7.50 26.5 62 1355 MC 15 27 63 135U MC 30 7.50 26.5 6h iJ*o5 LCV 2 11 27 65 1U02 LCV 10 27.5 66 1U10 LSV 2 11 . 7.50 27.5 .386 2 lj.09 6-2I1 0210 El 2 7.1*5 25 1.35U .1*75 1.961 10 0205 E2 2 25 1.596 .780 .1*35 11 0202 E3 2 7.13 1.57a .895 2.168 .1*51* 12 0155 RSM 2 25.5 1.596 .880 .1*1*3 13 oiii5 RCM 2 7.15 26 1.51*1 .905 1.839 .1*50 lij RCM 10 25.5 1.508 .920 .1*53 15 Olho MC 2 7.25 26 1.673 .920 1.991* .1*1*3 16 MC 15 26 .96 9 .910 .1*1*1 17 MC 30 7.20 26 1.376 .915 2.671 .1*38 18 0130 LCV 2 26.5 1.1*75 .9U0 .1*60 19 LCV 10 26 1.593 .935 .1*61* 20 0125 LSV 2 7.15 26 1.783 1.220 2.081* .1*28 h9 13U6 El 2 15 8.20 1.111 .527 2.1*32 .1*23 50 1350 E2 2 12 1.256 .800 .1*57 51 1357 E3 2 13 7.1*0 1.189 .900 2.168 .1*55 52 11*01 RSM 2 16 1.256 .870 .1*39 53 11*12 RCM 2 13 7.20 1.1*33 .925 2.290 .1*51* 514 RCM 10 13 2.133 . 91*0 .1*51* 55 11*18 MC 2 13 7.30 1.300 .915 2.322 .1*1*1 Chloro- DO DO Incu- NH3 mg/I N TOC phyll a BOD DO Light Dark bation C02 itik/1 ws/i mg/1 m«/l nw/1 ma/1 tine-out as/1 .001 12.32 202.5 8.66 9.70 5.2 .500 7.80 171.0 11.16 8.a .81*1* 9.67 107.3 8.19 5.71 1.017 8.1*0 96.0 a.67 1.067 6.57 95.3 7.08 1*.60 10.0 1.120 7.12 99.0 U.58 1.067 7.66 60.8 7.18 14.1*9 10.6 1.120 6.81* 82.5 a.38 1.200 6.57 75.8 7.71 1*.10 11.0 1.101 7.30 96.0 1*. 21* 1.180 5.88 252.0 U. 20 1.260 6.71* 98.3 7.58 5.01 9.1 170.3 12.29 11*. 06 11.39 1715 27.8 120.0 11.63 108.8 5.86 7.03 a.70 1915 12.0 67.5 5.1*1* 90.0 5.58 8.82 6.03 1915 8.a 71.3 3.75 ia.0 77.3 5.21* a. 96 3.78 1915 69.8 1*. 09 81*. 0 2.96 3.66 2.aa 1915 12.6 75.8 1*. 29 1*9-5 5.20 112.5 7.02 6.69 5.02 1915 ia.o .500 6.28 131.3 9.1*3 9.33 3.6 .693 86.3 8.15 .863 1*.75 78.8 5.61 a.69 9.7 .91*8 82.5 a.1*1* 1.052 3.23 61.5 3.86 5.33 10.0 1.085 71.3 a.2a 9.a 1-059 2*. 01* 71.3 6.01 5.25 1.007 69.0 a. 18 1.111 1*.10 69.8 6.1*7 3.89 10.0 .971* 75.0 a.12 1.033 86.3 a.3a 9.8 1.190 3.66 75.0 6.83 a.69 .701 8.88 90.0 8.a5 10.86 7.80 I7a5 6.0 .885 86.3 7.91 11.a 1.135 6.59 67.5 6.a3 6.5a a. 35 i7a5 1.216 62.3 5.12 1.287 6.59 72.8 a.ia a.95 3.66 17 a5 9.8 1.311* 75.0 a.25 8.2 1.217 5-71* 57.8 3.90 5.oa a.1*1 i7a5 ------- Date Time Sample Sample Secchi Water Total P Inorganic "Tr52^03 Chloro- DO DO Incu- Sample Sample Sample Loca- Depth Disk Field Temp P0J* P POJ^ TKN mg/1 NH3 TOC phyll a BOD DO Light Dark bation CO2 Number Taken Taken tion Feet Inches PH °C mg/1 mg/1 mg/1 N N0-)-N mg/1 N mg/1 Wl/1 mg/1 mg/1 mg/1 mg/1 tin®-out Bft/1 Station 6 - Broad Creek - -Continued 700621*56 6-21* 11*18 MC is 1.256 .91*5 .l<53 1.310 81.0 3.1*1 SI MC 30 7.20 1.767 1.005 2.129 .1*1*1 1.310 7.23 5U.8 3.70 3.53 17U5 10.2 58 11*25 LCV 2 13 1.500 .970 .1*1*1 1.237 71.3 1*.21 59 LCV 10 1.833 .990 .1*50 1.322 75.0 6.30 60 1U32 LSV 2 12 7.1*0 1.1*1*)* 1.065 2.716 .1*36 1.160 6.1*2 91.5 5.68 6.19 U.27 171*5 9.8 072209 7-22 1035 MC Surface 12 26 1.215 . 9U5 1.766 .826 1.115 5.1*7 51.0 7-78 3.72 7.1*1* 3-52 15U5 10 MC 15 25.5 1.189 .955 1.979 .833 1.058 5.1*7 33.8 7.53 3.86 7.27 3.31 15U5 Station 7 - Piscataway Creek 70062213 6-22 1213 El 2 9 8.90 26 168,8 11.1*8 12.20 10.09 .6 lit 1220 E2 2 10 8.00 26.5 106.5 6.99 6.1* 15 1230 E3 2 13 7.70 26.5 56.3 5.29 8.00 6.23 9.0 16 1236 RSM 2 12 7.65 26.5 60.0 6.1*7 8.0 17 1250 RCM 2 12 7.50 26.5 60.0 U.91 5-57 1+.1*3 ll*.U 18 12l*5 RCM 10 7.50 26 52.5 U.02 12.0 19 121*2 RCM 20 7.50 26 55.5 U.12 12.0 20 1317 MC 2 lk 7-50 27 33.8 a. 57 5.15 3.93 1715 9.0 21 1310 MC 10 7.1*0 26 59.3 3.99 11.8 22 1305 MC 20 7.1*0 26.5 1*5.0 3.71* 11.0 23 1300 MC 30 7.1*0 26 52.5 3.96 1*. 89 3.61 1715 11.0 2h 1255 MC 1*0 7.1*0 26 51.8 3.87 i*.bi* 3-52 13.6 25 1327 LCV 2 lk 7 - UO 26.5 51.0 11.3 26 1325 LCV 10 7-50 26.5 1*5.0 3.1*0 13-6 27 1323 LCV 20 7.1*0 26 36.8 1*.02 ll*.8 28 1333 LSV 2 13 7-50 26.5 1*8.8 3.87 6.77 2.88 1715 13.6 2321 6-23 0100 El 2 7.75 25-5 1.929 .710 1*.1*81* .51*5 .600 9.85 125.3 8.81 8.1*2 6.1* 22 125U E2 2 26 1.682 .850 .630 1.11*7 6.81* 90.8 5.00 23 121*8 E3 2 7.55 26 1.61*9 .880 2.729 .635 1.107 7.52 89.3 7.12 1*.79 9.3 21* 121*2 RSM 2 26 1.682 • 593 .635 .31*0 10.26 221*.0 12.61 25 1232 RCM 2 7.51 26 1.368 .865 2.587 .700 1.120 5.10 97.5 7.65 U.99 11.0 26 RCM 10 26 1.1*02 .870 .720 1.133 8.03 90.0 27 RCM 20 25.5 1.323 .885 .700 1.093 7.66 113.3 5.01* 28 1215 MC 2 7.50 26 1.290 .870 2.671 .790 1.233 5.1*7 89.3 8.08 5.1*6 10.2 29 MC 10 26 1.1*36 .81*5 .820 1.21*0 9.13 95-3 5.03 30 MC 20 25.5 1.323 .81*5 .805 1.227 5.1*1 97.5 5.12 31 MC 30 7.50 1.850 .875 2.61*5 .810 1.267 98.3 7.1*3 U.91 10. k 32 MC 1*0 25.5 1.1*02 .865 .785 1.21*0 6.1*2 96.0 1*. 89 33 MC 50 7.1t5 25.5 1.3ii6 .885 2.110 .790 1.267 16.87 93.0 7.23 1*.18 10.2 31* 1207 LCV 2 26 1.290 .850 .750 1.200 6.59 101.3 5.95 35 LCV 10 26 1.121 .785 .850 1.253 6.25 101.3 5.58 36 LCV 20 26 1.065 .855 .760 1.213 21.1*8 76.5 ------- Date Time Sample Sample Secchi Water Total P Inorganic NO2+NO2 Chloro- DO DO Incu- Sample Sample Sample Loca- Depth Disk Field Temp PO^ P POi, TKN mg/1 NH3 mg/I N TOC phyll a BOD DO Light Dark bation CO2 Number Taken Taken tion Feet Inches PH °C mg/1 mg/1 mg/1 N N0")-N mg/1 ^g/1 mg/1 mg/1 mg/1 *g/l time-out ng/1 Station 7 - Piscataway Creek -Continued 21.1*8 8.08 5.08 70062337 6-22 lll|8 LSV 2 7.55 26 1.08B .910 2.291 .710 1.273 90.0 6.13 9.0 67 6-23 12)6 El 2 16 7.60 27 112.5 6.66 8.59 1915 12.6 68 1218 E2 2 11 26.5 122.3 8.03 13.6 69 1221 E3 2 17 7.90 27 88.5 k.hh 6.52 a.5a 1715 70 1227 RSM 2 13 26.5 139.5 a. 93 9.8 71 1237 ROM 2 15 7.70 27 105.0 6.2a 7.76 5.72 1715 72 1235 ROM 10 26 111.8 5.90 73 1233 RCM 20 26.5 101.3 5.20 3.66 19.6 7U 12 53 HC 2 16 7.50 27 90.0 U.09 7.00 1715 75 1251 MC 10 27 75.0 3.63 76 12li8 MC 20 26.5 8O.3 3.59 16.1* 77 12l|3 MC 30 7.50 26.5 93.0 1.12 5.2a 3.57 1715 78 121*0 MC ao 26.5 108.8 3.7a 6.53 3.ai 1715 16.a 79 1303 LCV 2 12 27 103.5 a.73 80 1301 LCV 10 27 91*. 5 a. 3a 81 1300 LCV 20 12 26.5 53.3 5.56 82 1307 LSV 2 12 7.60 26 120.8 6.59 9.02 5.99 1715 Ui.a 2ij21 6-21+ 0110 El 2 7.15 25 1.1*20 .690 2.097 .1432 .771 3.01 8O.3 6.70 7.28 7.3 22 0105 E2 2 26 1.288 .835 .1*99 1.078 71.3 5.22 23 0100 E3 2 7.10 26 1.299 .835 2.355 .565 1.059 2.80 66.0 6.33 5.01 9.2 2h 0055 RSM 2 26 1.596 .631 .1*86 .555 112.5 10.98 25 001*5 RCM 2 7.20 26.5 1.398 .785 2.116 .612 .781* l*.ol* 69.0 6.58 5.6a 9.0 26 RCM 10 26 1.1*20 .770 .588 .837 81*. 0 5.56 27 RCM 20 26 1.398 .800 .603 • 935 106.5 5.30 28 001*0 MC 2 7.20 27 1.51*1 .830 1.310 .51*7 .961 a. 51* 81*. 8 5.1*3 6.35 10.9 29 MC 10 26.5 l.$ll .825 .1*91* 1.033 81.0 5-oa 30 MC 20 26.5 1.5U1 .830 .518 .91*1 81*. 8 5.12 31 0035 MC 30 7.10 26.5 1.321 .81*5 2.129 .51*6 1.033 1*.97 88.5 6.10 5-09 9.9 32 MC 1*0 26.5 1.156 .865 .517 1.01*6 86.3 a. so 33 MC 50 7.30 26 1.1*86 .855 2.013 .539 1.038 h. 51* 81*. 8 6.72 a. 81 8.3 3ii 0025 LCV 2 27 1.376 .790 .1*80 1.033 105.0 6.91 35 LCV 10 27 1.321 .800 .1*75 1.020 11*2.5 6.59 36 LCV 20 27 1.1*61* .80 5 .1*96 1.059 86.3 7.05 10.a 37 0016 LSV 2 7.38 26 1.1*31 .925 2.555 .1*1*1 1.111 5.19 75.0 7.29 5.1*1 61 1322 El 2 12 7.90 1.322 .805 3.000 .1*32 1.018 6.72 81*. 8 7.27 9.1*6 6.a5 17U5 9.1* 62 1315 E2 2 15 1.267 .895 .1*52 1.21*3 78.8 5.96 63 1312 E3 2 13 7.1*0 1.256 .865 2.265 .1*95 1.287 5.07 75.0 7.a2 7.25 a.69 nus 11.a 61* 1307 RSM 2 13 1.333 .735 .1*1*3 .561* 129.0 5.67 10.6 65 1302 RCM 2 13 7.50 1.311 .820 1.613 -552 1.166 6.97 123.8 5.21 7.a2 5.20 17a 5 66 RCM 10 1.156 .790 .671 1.078 86.3 a. 92 67 RCM 20 1.278 .800 .692 1.106 97.5 a. 87 9.0 68 1253 MC 2 18 7.50 1.389 .81*5 2.220 .520 1.195 6.93 95.3 6.10 9.05 5.16 17 a5 69 MC 10 1.1*11 .672 .1*51* 1.295 61.5 a. 12 ------- Sample Number Date Sample Taken Time Sample Taken Sample Loca- tion Sample Depth Feet Secchi Disk Inches Field pH Water Temp °C Total P Inorganic p pou mg/1 TK1I mg/1 i'J NO2+NO3 mg/1 NOi-N NH3 mg/1 H roc mg/1 Chloro- phyll a ^g/1 BOD mg/1 DO mg/1 DO Light mg/1 DO Dark mg/1 Incu- bation time-out C02 mg/1 Station 7 - Piscatawav Creek -Continued 51.8 3.78 70062^70 6-2li 1253 MC 20 1.333 .815 .U36 1.265 na5 71 MC 30 7.20 1.389 .855 2.lili5 .hlO 1.3ia 7.73 65.3 U.18 6.21 3.70 11.0 72 MC llO 7 .20 1.378 .795 .578 1.265 ? 2.0 a.25 i7a5 12.2 73 12ij0 LCV 2 111 1.356 .8U0 .hhh 1.332 80.3 3.96 7k LCV 10 1.333 .865 .hl9 1.355 67.5 3.96 75 LCV 20 1.1(67 .875 -U3U 1.362 71.3 3.78 8.85 5.65 na5 76 1227 lsv 2 16 7.60 1.300 .770 I.I18J1 • U3li 1.169 6.72 111.8 5.81 9.2 2 501 6-25 1105 El 2 12 7.90 27.5 60.0 3.67 10.15 5.13 1115 8.8 02 1100 E2 2 16 27 105-8 a. 06 6.3a 3.61 1115 03 1050 E3 2 111 7.60 27.5 51.0 a.27 11.0 Oil 10ti7 RSH 2 13 27 53.3 a.oa 1115 10.8 05 10U5 RCM 2 111 7.li5 27 63.8 a. 81 6.32 3.79 06 ioUo RCM 10 27 51.0 3.aa 07 RCM 20 27 5a. 8 3.57 2.68 1115 08 1036 MC 2 15 7.2i0 27.5 55.5 a.as 6.79 10.8 09 1035 MC 10 27 60.8 3.9a 10 1033 MC 20 27 sa.0 3.35 11 1030 MC . 30 7.30 53.3 3.16 5.80 2.81 1115 12.2 12 1025 MC ilO 7-ltO 26.5 61.5 3.ai 6.ai 2.72 1115 12.0 13 1015 LCV 2 7 27 66.0 3.53 lU LCV 10 27 56.3 3.75 15 LCV 20 27 70.5 a.20 6.60 1115 16 1005 LSV 2 10 7.70 26.5 lia.8 7.as 13-37 8.8 072007 7-20 09U0 MC Surface 7.30 26.5 a3.5 a. 52 10.02 3.75 1515 10.a 08 MC ho 7.20 25.2 63.8 a. is 10.37 a. 13 1515 27.8 2101 7-21 1350 MC Surface 1.20 26.5 a2.8 a. 53 6.76 a.62 1600 10.0 02 MC IlO 7.30 26.5 a9.5 a.aa 6.23 a. 01 1600 9.8 2211 7-22 1050 MC Surface 13 26 .962 .r/s 1.367 -auu 1.135 6.15 ai.3 7.90 a. 36 8.70 a. 15 I5a5 12 MC ilO 25.5 1.019 .673 1.362 .850 1.151; 6.38 51.0 6.95 a.37 8.55 3.97 i5as Station 8a - Gunston Cove 1615 70062229 6-22 1035 El 2 13 8.50 26 102.8 9.98 12.67 8.90 6.2 30 10U5 E2 2 13 8.10 26 sa.0 7.89 1615 7.0 31 1055 E3 2 12 7.50 25 62.3 7.22 9.08 6.31 6.6 32 1107 LSV 2 16 7.80 26 67.5 5.99 1615 5.6 33 mli LCV 2 16 7.70 26 69.0 6.01 8.03 5.20 7.2 31; 1130 MC 2 ' 13 7.J1O 27 109.5 6.06 7.69 a. 99 1615 9.a 35 1125 MC 15 7.60 26 52.5 a.79 1615 8.2 36 1120 MC 30 7.50 27 66.0 a.77 6.2a a. 32 11.0 37 nU5 RCM 2 lh 7.70 26 39.0 5.99 10.0 38 llllO RCM 10 7.55 27 6a. 5 5.78 1615 9.0 39 1150 RSM 2 9 7.60 26 50.3 6.6a 7.79 6.05 8.8 ------- Sample Number Date Sample Taken Time Sample Taken Sample Loca- tion Sample Depth Feet Secchi Disk Inches Field PH Water Temp *C Total P pok mg/l Inorganic P P0h mg/1 TKN rag/1 N NO2+NO3 mg/1 N0-,-N NH3 mg/1 N TOC mg/1 Chloro- phyll a t*g/l ~ BOD mg/1 DO mg/1 DO Light mg/1 DO Dark mg/1 Incu- bation time-out C02 aa/1 Station 8a - Gunston Cove -Continued 70062338 6-22 1058 El 2 8.95 26 .81? .317 2.1*20 .295 .001 22.83 202.5 10.89 7.19 5.2 39 1157 E2 2 8.1(0 26.5 .836 .31*6 .91*0 <.100 23.09 120.0 9.1*6 1*0 1101* E3 2 7.75 26 .929 .627 2.881* 1.851* .625 21.11* 99.0 8.28 6.91 9.1* 1*1 1110 LSV 2 7.52 26.5 .911* .655 1.067 .700 10.52 108.8 6.86 6.1* 1*2 1116 LCV 2 7.80 26.5 .830 .528 1.971* 2.667 .260 6.09 112.5 7.5U 7.06 1*3 1120 MC 2 7.1*0 26 .828 .555 1.671 2.875 .280 7.73 117.8 7.57 7 - 2ii 8.1* U* MC 15 26 .905 .552 2.817 .325 72.71* 97-5 6.20 8.8 1*5 MC 30 7.1*5 26 .985 .573 1.516 2.758 .1*50 6.21 97.5 7.65 6.71* 1*6 1130 RCM 2 26 .953 .616 2.61*2 .600 5.59 82.5 5.81* 1*7 RCM 10 26 .967 .627 2.583 .625 6.09 96.0 5.92 1*8 1137 RSM 2 7.80 26.5 .758 .1*91* 1.529 3.1*79 .11*0 18.60 67.5 6.11 8.15 5.0 83 6-23 1102 El 2 12 9.30 26.3 191.3 6.01* 19.65 13.55 1615 81* 1105 E2 2 11* 27 133.5 6.95 85 1112 E3 2 11* 8.00 27 127.5 7.1*7 9.83 5.87 1615 6.2 86 1117 LSV 2 13 26.5 llU.O 6.90 87 1121 LCV 2 1U 7.70 27 116.3 6.75 9.87 6.05 1615 9.1* 88 1125 MC 2 16 7.80 27 102.0 6.21* 9.71 6.11 1615 12.2 89 MC 15 26.3 101*. 3 6.59 90 1128 MC 30 7.50 26.5 99.0 5.20 7.38 i*.6l 1615 10.6 91 111*0 RCM 2 15 27 132.8 1*.87 92 1135 RCM 10 27 99.8 7.81* 1615 93 111*5 RSM 2 15 7.90 27 117.0 7.31 10.96 6.38 11.6 21*38 6-23 2320 El 2 8.00 26.5 .808 .370 1.91*9 .367 .001 5.19 11*6.3 9.1*9 It*.78 39 2330 E2 2 26 .992 .603 .700 .710 95.3 7.90 1*0 2333 E3 2 7.35 26 .971 .631 2.191* .930 .555 1*.06 93.8 6.80 6.27 8.2 1*1 2337 ISV 2 26.5 .991 .583 .61*5 .700 105.0 7.67 1*2 231*0 LCV 2 7.1*1 26.5 .91*5 .1*1*6 1.290 1.0I4J4 .360 1*.10 93.8 6.85 7.1*0 6.2 1*3 2350 MC 2 7.25 26.5 .963 .550 1.639 1.083 .1*50 3.66 126.0 6.67 6.77 9.3 1*1* MC 15 26 1.035 .583 1.059 .61*0 78.8 6.61 8.1* 1*5 MC 30 7.30 26 1.0U0 .625 1.536 1.053 .650 It. 51* 93.8 7.09 6.01 1*6 2357 RCM 2 26 1.068 .612 .952 .730 90.0 5.83 1*7 RCM 10 26 1.132 .652 .91*6 .700 69.0 6.11 1*8 21*00 RSM 2 7.10 .776 .1*50 1.168 1.175 .001 2.80 61.5 5.87 8.70 5.9 77 6—21* 1115 El 2 13 8.70 1.189 1.71*2 .782 .250 8.75 101.3 3.07 11*.53 9.71* 1630 3.1* 78 1122 E2 2 11 1.133 .765 .560 122.3 11.16 79 1130 E3 2 10 8.20 1.111 .529 1.1*78 .81*1 .250 9.80 115.5 9.72 11.39 6.36 1630 5-2 80 1136 LSV 2 12 1.167 .608 .893 .550 123.8 8.13 81 111*3 LCV 2 12 7.30 1.222 .587 1.161 l.Oll* .530 7.73 100.5 6.26 9.77 t».76 1630 8.8 82 1150 MC 2 13 7.1*0 1.167 .600 1.91*2 1.032 .51*0 8.28 97.5 5.12 9.30 5.30 1630 10.8 83 MC 15 1.167 .602 1.08U .520 105.0 5.09 81* MC 30 7.30 1.111 .570 1.387 1.182 .310 6.85 99.8 5.12 7.02 a.39 1630 9.8 85 1200 RCM 2 15 1.133 .600 1.051* .530 112.5 5.20 86 RCM 10 • 990 .625 1.008 .535 108.8 6.32 87 1206 RSM 2 13 7.1*0 .961* .612 1.871 .968 .560 6.1*6 107.3 6.67 10.1*6 5.19 1630 10.a ------- Date Time Sample Sample Secchi Water Total P Inorganic NO0+NO3 Chloro - M DO Incu- Sample Sample Sample Loca- Depth Disk Field Temp P01, P PO^ TKN mg/1 HH3 TOC phyll a BOD DO Light Dark bation CO2 Number Taken Taken tion Feet Inches PH °C mg/1 mg/1 mg/1 N NO^-N i ng/1 N mg/1 tig/1 mg/1 mg/1 mg/1 mg/1 time-out mg/1 Station 8a - Gunston Cove -Continued 70072011 7-20 1015 MC Surface 7.60 27 72.8 7.10 12.55 6.38 1515 7.2 12 MC 20 7.h2 27 99.8 6.19 11.30 5.13 1515 8.3 2105 7-21 1315 MC Surface 7.25 26 69.8 5.55 9.09 5.67 1530 7.6 06 MC 25 7.30 26 91+.5 5-71 8.61 5.51+ 1530 7.8 2215 7-22 1115 MC Surface 1U 26 .691 .297 1.000 .981 • 311 5.1+7 106.5 5.32 6.31+ 16 MC 20 25.5 • 8Ul .366 1.31+6 .991 .312 6.57 110.3 6.15 5-69 Station 8 - Dogue Creek 70072009 7-20 1005 MC Surface 7.60 27 92.3 6.70 12.63 6.30 1515 9.0 10 MC 20 7.1+5 27 87.8 5.91+ 12.20 5-1+5 1515 8.6 2103 7-21 1330 MC Surface 7.15 26 66.0 5.07 7.51 7.38 1530 8.1+ 0U MC 20 7.20 26 75.0 It.71+ 6.96 1+.60 1530 9.0 2213 7-22 1150 MC Surface 13 26 .775 • 51+3 1.207 .921+ .865 6.15 72.8 5.72 6.28 11.73 5-35 151+5 lh MC 20 25-5 .826 • 51+2 1.133 1.000 .689 6.29 82.5 5.71 5.1+5 11.02 5.25 151+5 Station 9 - Hallowing Point 8a.0 6.50 6.35 1515 6.6 70072013 7-20 1035 MC Surface 7.65 27 12.27 11* MC 20 7.50 27.5 96.8 6.38 11.35 5.62 1515 8.2 . 2107 7-21 1300 MC Surface 7.1+0 25.5 66.0 6.96 9.71 5.77 1530 6.6 08 MC 20 7.50 25-5 120.8 6.00 9.1+3 5.50 1530 6.8 2217 7-22 1125 MC Surface 12 26 .679 .3 78 1.001 .991 .156 6.38 105.0 5.U1 6.59 12.05 5.71+ 15U5 18 MC 20 25.5 • 739 ¦ 370 1.112 .81+3 .091+ 9.03 87.8 6.15 6.31 12.06 6.11+ 151*5 Station 10 - Indian Head 70072015 7-20 1050 MC Surface 7.1+0 27 87.0 6.39 11.62 5.77 1515 8.6 16 MC 35 7.30 27 88.5 5.01+ 9.90 1+.1+8 1515 8.1+ 31 MC Surface 7.35 27 1.900 8.072 681.8 >26.01+ 8.5 2109 7-21 1250 MC Surface 7.ii0 26 86.3 6.58 9.75 6.11 1530 6.2 10 MC 35 7.25 25.5 91.5 5.87 8.82 5.1*2 1530 6.8 2219 7-22 liao MC Surface 15 26 .679 .369 1.101 .972 .057 8.21 78.8 9.09 6.21+ 11.28 5.62 151+5 20 MC 35 25.5 .758 .378 .915 .875 .038 8.03 90.0 1+.95 5-85 11.61 5-57 151+5 7.1+5 Station 10A - Occoquan Bay 70072017 7-20 1120 MC Surface 27 62.5 6.82 11.51 6.30 1515 7.a 18 MC 20 7.35 27 71+.3 10.32 5.22 1515 7.6 2111 7-21 1235 MC Surface 7.1+0 26 101.3 6.32 9.88 6.23 1530 6.0 12 MC 20 7.30 25.5 93.8 5.29 10.11 5.51+ 1530 6.8 2221 7-22 1150 MC Surface 15 25.5 .61+3 .366 •995 .972 .029 6.83 73.5 1+.50 6.52 22 MC 20 25.5 .768 .365 .787 . 972 .026 7.25 93.8 7.25 6.12 Station 11 - Possum Point 70072019 7-20 MC Suri'aue 7-70 28 86.3 6.58 10.00 6.26 1515 6.a 20 MC 20 7.50 28 79.5 6.38 9.1+2 5.82 1515 6.a ------- Sample Number Date Sample Taken Time Sample Taken Sample Loca- tion Sample Depth Feet Secchi Disk Inches Field PH Water Temp °C Total pok mg/l P inorganic M02+N03 P PO^ TKfl mg/l mg/l mg/l N NO3-N NH3 mg/l N TOC mg/l Chloro phyll ^k/i a BOD hir/I DO mg/l DO ' Light mg/l DO Dark mg/l Incu- bation tiae-out C02 B3/1 Station 11 - Possum Point -Continued 6.8 70072113 7-21 1210 MC Surface 7.50 26.5 lU3 - 3 7.66 12.93 7.31 1530 111 MC 25 8.00 26 89.3 9.58 5.67 1530 U.B 2223 7-22 1210 MC Surface 13 26 .855 • 3?1 2.032 .95U .025 12.0U 127.5 8.36 8.23 1U.23 7.60 15U5 21* MC 20 26.5 .61* 0 .387 .931 .935 .022 5.1l7 73-5 h.97 6.18 10.12 5.92 151*5 Station 12 - Sandy Point 6.0 70072021 7-20 1205 MC Surface 8.10 29 69.8 8.06 11.56 7.58 1515 22 MC 20 7.80 29 71.3 6.77 9.15 6.10 1515 5.6 211? 7-21 1150 MC Surface 7.U0 26 ii7.3 6.09 8.01* 5.68 liiio 6.2 16 MC 20 7.50 26.5 6U.5 5.71 7.68 5.52 il*io 6.0 222? 7-22 1230 MC Surface 17 26 .671 .1*1*3 .683 .016 5.88 81.0 3.81; 6.1*2 io.l*5 6.26 15U5 26 MC 20 25.5 .872 .530 .815 .023 6.02 27.8 U-63 5.1i 9 8.89 5.19 i5U5 Station 13 - Smith Point 7 007 2 023 7-20 1230 MC Surface 8.20 28.5 81.0 7.75 10.29 7.27 1515 6.8 2l| MC 20 7.50 28 101.3 6.21 8.53 5.90 1515 l*-6 32 MC Surface 8.20 28.5 2.110 9.115 988.5 >21.58 1*.6 2117 7-21 1130 MC Surface 7.60 26 59.3 6.37 8.20 5.96 ii*lo 6.0 18 MC 20 7.55 25.5 20.3 5.98 7.86 6.01 11*10 5.2 2227 7-22 121*5 MC Surface 13 26 .81*9 .582 .808 .017 6.15 514.8 5.ol* 7.17 10.55 7.17 15U5 28 MC 20 25.5 1.075 .661 .787 .OliO 5.65 18.8 3.7li 6. U3 8.1*7 5.50 151*5 Station lii - ¦ Maryland Point 7007202? 7-20 1300 MC Surface 7.80 29 1|6.5 7.10 7.78 6.83 1515 6.0 26 MC 25 7.ho 29 56.3 6.13 6.63 5.7li 1515 7.0 2119 7-21 1110 MC Surface 7.20 26 16.5 5.71 7.22 5.U1 11*10 6.8 20 MC 25 7.1i5 25.5 36.0 5.59 7.15 5.63 11*10 7.2 2229 7-22 1300 MC Surface 13 26 .9 28 .738 .659 .018 5.11 37.5 2.81 5.85 7.97 5.90 151*5 30 MC 30 25.5 1.189 • 775 .613 . 03li 6.03 36.0 U.28 5.18 7-liO 5.21 151*5 Station 1? - Nanjemoy Creek 70072027 7-20 MC Surface 7.80 28 52.5 6.67 7.51| 6.31 1530 7.6 28 MC 20 7.30 28 30.0 5.50 5.80 5.01 1530 8.2 2121 7-21 1050 MC Surface 7.20 25.5 33.0 5.1i6 7.15 5-1+5 11*10 7.6 22 MC 20 7.10 25 30.8 5.39 6.52 5.51 11*10 7.8 2231 7-22 1320 MC Surface 15 26 .792 .718 .319 .059 5.20 39.0 6.00 7.78 5.76 15U5 32 MC 20 25.5 .872 .725 .910 .301 .059 5.1i7 22.5 .10 5.05 6.20 l*.7l* 151*5 Station 16 - Route 301 Bridge 70072029 7-20 1355 MC Surface 7.90 27 Ii3.5 7.21* 7.62 7.11* 1530 5.6 30 MC 30 7.50 26.5 30.0 6.09 6.07 5.99 1530 6.8 2123 7-21 1010 MC Surface 7.35 2U.5 97.5 6.19 8.2? 5.68 1U10 7.0 21| 13?0 MC 35 7.20 25 18.0 5.75 6.97 5.55 11*10 7.1* 2233 7-22 MC Surface 20 25.5 .736 .653 .878 .239 '.02 k U.51 17-3 5.90 6.77 6.18 1600 3ll MC 30 25.5 .792 .636 .867 -17l| .058 li.3B 9.0 .51* 5.28 5.71* U.99 1600 M O ------- INSERT A INSERT SCALE IN MILES POTOMAC ESTUARY DISSOLVED OXYGEN BUDGET STUDIES 1970 5 0 5 10 tjBH n-n, iiimnm ¦¦¦¦¦¦« i SCALE IN MILES ------- |