IH ANNAPOLiS FIELD OFFICE SITUATION REPORT POTOMAC RIVER WORKING FOR A BETTER ENVIRONMENT : ENVIHONMENTAL PROTECTION U.S. EPA ANNAPOLIS FIELD OFFICE, ANNAPOLIS SCIENCE CENTER, Amnpolit, IW. 21401 ------- 9O3R769Q3 SITUATION REPORT POTOMAC RIVER May 25, 1976 ------- I. HISTORY When Captain John Smith explored the Potomac River in 1608 the waterway was virtually in a pristine state with abounding fish life. The crude and limited agricultural activities of the indigenous Indian tribes had little impact on the aquatic environment. In the late 1790's it was reported that President Adams swam in the Potomac Estuary near Washington, D.C. It was about this time that canals were carved along the river and com- mercial shipping activities took place in the estuary. As the population in the Washington Metropolitan Area grew, so did water pollution problems in the Potomac Estuary. The dumping of raw municipal wastes into the river became so extensive that by the early 1860's President Lincoln fre- quently was forced to leave the White House at night due to objectionable sewage odors. Following the Civil War the sewage situation worsened to the point that President Harrison ordered a system to be devised to convey all sewage to a point in the river downstream of Washington, D.C.thus collec- i tion and transfer of the problem became the first solution to the municipal waste dilemma. It was not until 1938 that sewage treatment measures were employed in the estuary area, and by this time water quality problems had become quite evident. Even though sewage treatment measures were em- ployed pervasively, excessive population growth more than offset pollution abatement efforts. Historically and to this day the primary cause of water pollution in the Potomac Estuary is municipal waste. Nonpoint sources of pollution, including agricultural runoff and stormwater loadings, also contribute significant amounts of pollutants to the Potomac. II. CURRENT STATUS The current problem facing the Potomac River and Estuary is an inter- related one consisting of a marginally sufficient water supply, variable ------- water quality in the upper reaches of the estuary due to advanced eutrophication (over fertilization of nutrients), and problems of as yet undetermined magnitude as regards toxic metals and organohalogens and their effects on living organisms in the Potomac. The Washington Metropolitan Area is a rapidly growing region with about 2.8 million people. Present municipal water use is 370 mgd with 72 percent (265 mgd) supplied from the Potomac River above Washington (Great Falls). Projected population and water supply needs are shown in Table I. Present resources are insufficient to supply peak needs during sustained low flows. (See Table II.) It is very possible that a drought could recur as in 1966 and 1969 where the metropolitan water supply would be seriously depleted, if not inadequate to meet water supply needs since the maximum demand of record has exceeded the minimum flow, though fortunately not at the same time. The concurrence of these adverse conditions is not hypothetical and a number of alter- natives are being considered to alleviate this situation. The U.S. Army Corps of Engineers has proposed three alternative impoundment systems for water supply augmentation. (See Table III.) Use of the freshwater portion of the estuary for emergency water supply during sustained low flow periods would meet any immediate crisis since the lead time for construction of impoundments is approximately 10 years after approval. The water supply situation has been further complicated by the Montgomery County decision to construct a municipal sewage treatment ------- TABLE'I Water Supply Needs Year 1969 .1980 2000 2020 Population 2,700,000 k, 000, 000 6,700,000 9,300,000 Yearly avg. (mgd) 370 570 1010 1570 Maximum Month (mgd) .1*7° . 720 1310 20l;0 Maximum Daily (mgd) 660 1000 1820 , 2820 TABLE II Low-Flow Characteristics Before Water Supply Diversion Withdrawal from the Potomac Estuary or from Direct Reuse*- Recurrence. Interval (years) 20 50 Minimum Monthly Fresh Inflow (mgd) 1300 1170 910 1900 For a 720 mgd Need (mgd). none none none 2000 For a 1310 mgd "Need (mgd) 210 2020 For a 20ljO mgd Need (mgd) 600 1070 1330 Withdrawal based on minimum 30-day low flow concurrently with a maximum 30-day water supply withdrawal and a 200 mgd minimum base flow over Great Falls into the estuary TABLE III Bloomington Bloomington, Verona, and Sixes Bridge Bloomington, Verona, Sixes Bridge, Town Creek, North Mountain, Sideling Hill, and Little Cacapon System I II III ------- plant discharging to the Potomac River above the metropolitan water intakes at Great Falls. Various alternatives pertaining to this * plant are still undecided, namely siting, plant design/capacity and degree of treatment required and most important its effects on the water supply of Metropolitan Washington. The wastewater disposal problem in the upper reach of the estuary from Great Falls to Indian Head, Maryland, results from the discharge of 325 mgd of municipal sewage from 18 facilities, of which the Blue Plains plant of the District of Columbia is the largest (Fig. I). Of the 325 mgd, 45.5, 23.1, and 35.4 percent, respectively,. come from Maryland, Virginia, and the District of Columbia. Since 1913 wastewater volumes have increased eightfold, from 42 to 325 mgd. Similar trends have occurred for total nitrogen and phosphorus with 10-fold and 24-fold increases, respectively. Table IV shows waste- water loading trends of the Washington Metropolitan Area. Increased wastewater loadings to the upper Potomac Estuary have resulted in increased amounts of nutrients and consequently the wore frequent occurrence of nassive, -undesirable algal blooms. Under summer and fall conditions large populations of blue-green algae (pollution tolerant), mainly Anacystis sp., are predominant in the freshwater portion of the estuary. These algae are not grazed by higher trophic forms and are therefore useless in the food chain. When excessive mats of these blooms expend their life cycle and decay, dissolved oxygen in the v/ater is reduced below acceptable levels to sustain fish life. ------- POTOMAC RIVER ESTUARY \YASTEWATER TREATMENT PLANTS ANNAPOLIS FICLD OFFICE EPA ;97I N \ WASHINGTON D.C. PENTAGON Q (I.Omgd.) ' RIVER MILES FROM CHAIN SR'DGE-'0 ARLINGTON I40mgd.) WootJrow Wilson Memoriol ZONE VIRGINIA ALEXANDRIA SSS (Si mgd.) V.'ESTGATE LITTLE HUNTING Cr.JZI 'V DOGUE Cr. y^L. A-' FORT BELVOiR LOV.'ER POTOMAC (SGroodl.) PISCATAWAY Cr. (90 rr. ^/DISTRICT OF COLUMBIA (3O9mgd.) RIVER MILES FROM CHAIN BRIDGE = 15 BROAD CREEK ANDREWS A.F.B. ZONE MARYLAND RIVER MILES FROM CHAIN BSiOGf. = 3Or EXISTING WASTEV.'ATER TREATMEN'T PLANTS (PROJECTED FULL DEVELOPMENT CAPACITY) D EXISTING'PLANTS TO EC ABANDONED ------- TABLE IV WASTEWTER LOADING TR3IES VASHE&TOtf MUTKOPOLITA:? AREA Year 1913 1932 1544 1954 1957 19&0 196; 1063 1969 17/0 Population _ S?rvod 320,000 575,000 1,149,000 1,350,000 l,6eO;000 1,360,000 2,100,000 2,415,000 2,450,000 2,535,000 Flovfl "toed) . 42 75 167 195 210 222 265 31? 320 322 Untreated ' 5-Pr,y_DOD (Ibo/day) 58,000 103,000 235,000 280,000 305,000 370,000. 417,000 4245,000 439,000 484,000 Rejnovnl 5-Ctvy BOD * 0 0 40 28 33 70 70 70 71 1- 71 Treated 5-Dnv y30D (Ibo/day) 58,000 . 103,000 141,000 200,000 204,000 110,000 125,000 130,000 129,000 141,000 Ultisatefa Car, 7JOD (Iba/doy; 84,000 149,000 205,000 290,000 297,000 160,000 182,000 188,000 185,000 aC4,000 Ultimate f 4 NU. POD .(ibb/cfcy) 29,000 52,000 105,000 145,000 153,000 170,000 192,000 226,000 222,000 254,000 Total1 Ultimate 300 ( r\nr* + >Mt \ ll T 111 ' * " * L (Ibo/doy) n3,oco 201,000 310, 000 435,000 450,000 330,000 . . ;S4,CCO , 414,000 408,000 456,000 Total ItiliSSTJ!! (Ita/cU^) 6,400 11,400 23,000 31,700 33,500 37,200 42,000* 50,000 55,000 cO,COO Total ?io3. f'?? (Ifej/day) X,1CO 2,000 4.0CO 5,500 8,600 10,000 ie,3co 20,100 21,100 24, COO 1, Includes estimated sewer overflow loadings 2. Ultirato carboriflccoras EOD « l,/,5 x 5-day SOD - 3. Ultlratc nitrccono'JS BOD " 4.57 x unoxidizcd nitrogen ------- In the saline portion of the estuary, growth of marine phyto- . plankton known as "red tides" proliferates, aggravated by the high nutrient content in the water. These have teen known to assume forms toxic to fish life. The overall effect of increases in nutrient loadings since 1913 (Table IV) on dominant plant forms in the upper estuary has been continuous and dramatic. Figure II visualizes the successive domination of various plant forms leading to the present state of persistent massive summer blooms of the blue-green alga Anacystis in nuisance concentrations of greater than 50 micrograms per liter from the metropolitan area downstream as far as Maryland Point. This condition still persists and will probably increase in intensity unless the nutrient discharges are significantly reduced. The major detrimental effects of the wastes being discharged to the Potomac are: (1) An abundance of nutrients which causes over-enrichment of the estuary; (2) Depletion of dissolved oxygen creating zones of depressed oxygen levels; (3) High bacterial densities which preclude use of the river for any contact recreational activities and as a potable water supply source. Approximately 50 million tons of sediment are deposited into the river each year, with 39 percent of it generated in the Washington Metropolitan Area. Stringent regulation is needed to ------- WASTEWATER NUTRIENT ENRICHMENT TRENDS AND ECOLOGICAL EFFECTS UPPER POTOMAC TIDAL RIVER SYSTEM 20.000 15.000 «~ O o 10.000- O 5,000- O 33 m NO MAJOR PLANT NUISANCES WATER CHESTNUT INVASION V/ATER MILFOIL INVASION LOCAL BLUE-GREEN ALGAL BLOOMS MASSIVE PERSISTENT DUIE-GHEEN ALGAL BLOOM NITROGEN ^^~-~ PHOSPHORUS r250.000 200.000 150.000 to -a u: >» < S u 2 loo.ooo 3 K o 50.000 ------- control this obvious pollutant and minimize its harmful potential. Maryland and the District have specific sediment control ordin- ances in effect. . : In the Washington Metropolitan Area, the amount of water used for manufacturing is insignificant. The major industrial use is as cooling water. There are currently six major cooling water users in the Potomac River tidal system with another being proposed near Sandy Point. The total cooling water use is 2,71*8 mgd as follows: Facility . PEPCO at Benning Rd. (Washington, B.C.) PEPCO, Buzzard Point (Washington, B.C.) Virginia Heating (Arlington, Va.) PEPCO Generating Station (Alexandria, Va.) VEPCO, Possum Point (Quantico, Va.) PEPCO, Sandy Point PEPCO, Morgantown (Charles Co., Md.) Water Usage Receiving Water (mgd J 568 570 ho Anacostia River Anacostia River Remarks Also Uses Cooling Towers Uoo 720 Boundary Channel of Potomac Estuary Potomac Estuary Potomac Estuary Potomac Estuary Potomac Estuary Proposed Facility Ultimate Usage to be llUiO mgd TOTAL ------- Navigational use of the Potomac Estuary waters is primarily to provide commercial transport via ^-iver barges. Two commercial firms presently transport various petroleum products from .tank farms located in the lower Potomac and in the Chesapeake Bay pro- per to the Washington Metropolitan Area. Sand and gravel mining is also a water related industrial use of the estuary bed. Currently, dredging for this purpose is being conducted in the estuary below Indian Head, Maryland. * Recreational facilities on or near the Potomac estuary in- clude a national park, three state parks, seven fish and game areas of 226 county recreational sites. A study by the Bureau of Outdoor Recreation indicated that the recreational potential of the 63? miles of shoreline has barely been developed. Few public beaches have been opened primarily because of poor water quality (in the upper reaches) and to some degree the unwelcome presence of stinging jellyfish. . . The dockside value of fish, crabs, clams, and oysters taken . from the Potomac tidal system is about $5 million annually. Sport fishing contributes more than $0.6 million per year. There are approximately 95 marina facilities in the tidal Potomac which accomodate over 5,200 recreational watercraft. Ill PRESENT ANNAPOLIS FIELD OFFICE EFFORTS . The Annapolis Field Office currently monitors the Potomac estuary on a monthly basis. The sampling survey consists of 26 ------- stations (Fig. Ill) from Point Lookout to Chain Bridge and analyses are conducted for pertinent chemical and biological parameters re- lated to the hyper-eutrophic conditions existing in the estuary. Various intensive surveys have been conducted and documented in the past few years dealing with specific problems in the Potomac. These studies provide insight by focusing attention on one aspect of the pollution problem. . IV. CURRENT STATUS OF THE CORRECTIVE ACTION PROGRAM In 1969 the Potomac Metropolitan Area Enforcement Conference, initiated in 1957 as a means of bringing about cooperative action among the political jurisdictions, was reconvened. A memorandum of understanding was agreed upon which established a program for con- struction of sewage treatment facilities in accordance with the treat- ment requirements established in an AFO report. Construction is in progress at the B.C. treatment plant, Virginia treatment facilities are being upgraded, and Maryland has not as yet selected the sites for additional treatment plants. The Interstate Task Force has been set up to implement the program adopted by the Conference for the metropolitan Washington area. Upstream problems, with exception of the need to control nutrients reaching the estuary, are receiving the attention of the specific states involved. ------- /V OCCOOUA* txr PO31UM POINT- LEGEND © MAJOR WASTE TREATMENT PLANTS A CAGING STATION - WASHINGTON. DjC. A DISTRICT OF COLUMBIA 6 ARLINGTON COUNTY i C ALEXANDRIA SANITATION AUTHORITY D FAIRFAX COUNTY - WESTGATE PLANT E FAIRFAX COUNTY - LITTLE HUNTING CREEK PLANT F FAIRFAX COUNTY - DOGUE CREEK PLANT G WASHINGTON SUBURBAN SANITARY COMMISSION - PISCATAWAY H ANDREWS AIR FORCE BASE - PLANTS ONE. FOUR I FORT BELVOIR -PLANTS ONE. TWO. * J PENTAGON K FAIRFAX COUNTY - LOWER POTOMAC PLANT POTOMAC ESTUARY Figure III ------- |