The McMillan Reservoir is a

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contr ...

in Washington, D.C. that supplies the majority of the city's

municipal water Tap water (also known as faucet water, running water, or municipal water) is water supplied through a tap, a water dispenser valve. In many countries, tap water usually has the quality of drinking water. Tap water is commonly used for drinking, ...

. It was originally called the Howard University Reservoir or the Washington City Reservoir, and was completed in 1902 by the

U.S. Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

Construction history

The Macmillan Reservoir was built in 1902 on the site of Smith Spring, one of the springs previously used for drinking water. Washington's earliest residents relied on natural springs but this came to be inadequate as the city's population grew. In 1850,

Congress A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of ...

determined that the

Potomac River The Potomac River () drains the Mid-Atlantic United States, flowing from the Potomac Highlands into Chesapeake Bay. It is long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map. Retrieved Augu ...

should be the city's principal source of water.

Washington Aqueduct

A congressionally funded engineering study was conducted to determine the most available mode of supplying water to the city. Work and study conducted under the leadership of Lieutenant Montgomery C. Meigs culminated into the development of the Washington Aqueduct which began operations on January 3, 1859. Initially the system provided water to the city from the Little Falls Branch in

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean t ...

, until the aqueduct construction was completed. Regular water service from the Potomac River source through the aqueduct commenced in 1864.

Washington City Tunnel

In the early years of operation the water was routed through the system's two earlier-built reservoirs, Dalecarlia and Georgetown, which were designed to settle

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...

out of the water. In 1873 the Army began construction of a new water supply tunnel, led by Garrett Lydecker, a major in the Army Corps of Engineers. The tunnel was known as the Washington City Tunnel, to provide more storage,

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to the ...

and distribution capacity for the system. Lydecker predicted the tunnel would cost about $53,000 to build. Construction of the tunnel was halted in the 1880s due to a variety of problems including funding shortages, cost overruns, bribery and fraud associated with the construction process. During that period some improvements were made to the Dalecarlia portion of the system, and work on the tunnel finally resumed in 1898. The tunnel was completed in 1901, after an additional $800,000 expenditure, and the McMillan Reservoir began operation in 1902.

Filtration plant

By 1902 it became apparent that the sedimentation process in the several reservoirs was not effective against

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a g ...

s such as

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

, and was therefore not sufficiently protective of public health. To handle population growth and municipal sanitation needs, the city built the

McMillan Sand Filtration Site McMillan Sand Filtration Site is a twenty-five acre decommissioned water treatment plant in northwest Washington, D.C., built as part of the historic McMillan Reservoir Park. It is bound on the north by Michigan Avenue, on the east by North Capit ...

in 1905. This facility implemented an innovative

water purification Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids, and gases from water. The goal is to produce water that is fit for specific purposes. Most water is purified and disinfected for hu ...

system using slow sand filter technology to treat 75 million gallons (280 million liters) per day. It helped quell

typhoid Typhoid fever, also known as typhoid, is a disease caused by ''Salmonella'' serotype Typhi bacteria. Symptoms vary from mild to severe, and usually begin six to 30 days after exposure. Often there is a gradual onset of a high fever over several d ...

epidemics and other communicable diseases throughout the city. In 1907 the reservoir and filtration plant were named in honor of Senator James McMillan of

Michigan Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and t ...

, who chaired the Senate Committee on the District of Columbia and supported development of the water supply facilities. Congress officially designated the site as a park in March 1911. Subsequent improvements to the city water system were initiated beginning in the 1920s. The regular use of

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

as a

disinfectant A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than s ...

began in 1923 at the McMillan filtration plant. Another treatment plant was completed in 1928 adjacent to the Dalecarlia Reservoir using a newer technology, a

rapid sand filter The rapid sand filter or rapid gravity filter is a type of filter used in water purification and is commonly used in municipal drinking water facilities as part of a multiple-stage treatment system. Rapid sand filters were first developed in the ...

. In 1941, due to security concerns during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, the entire site was permanently closed and fenced off due to fear of sabotage. After the war, the property remained closed to the public, but continued to supply the city with filtered water. The growth of the city population led to further expansions at the Dalecarlia site in the 1950s. The slow sand filtration system at MacMillan was replaced with a rapid sand filtration system, built adjacent to the old system, in 1985. In 1986, the Army Corps of Engineers decommissioned the slow sand filtration site and declared it surplus. The old treatment site was purchased by the District of Columbia from the federal government in 1987 for $9.3 million, and the site began to deteriorate due to lack of maintenance. At that time DC government had no specific plan for the site. In 1991 the 25 acre (100,000 m²) McMillan Reservoir site, located between Michigan Avenue,

North Capitol Street North Capitol Street is a street in Washington, D.C. that separates the Northwest and Northeast quadrants of the city. Route description North Capitol Street begins at D Street in Lower Senate Park, between Louisiana and Delaware Avenues north ...

, and First Street in Northwest Washington, D.C., was designated a DC Historic Landmark. In 2000, and again in 2005, it was placed on the "List of Most Endangered Properties."

McMillan Fountain

The McMillan Fountain is a public artwork by

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

artist Herbert Adams located on the Reservoir grounds. The fountain, completed in 1912 and dedicated in October 1919, consists of a

bronze Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids suc ...

The Three Graces placed upon a pink

granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies un ...

base. Cast by Roman Bronze Works, the fountain was originally part of a large landscape setting designed by Charles A. Platt. A tribute to James McMillan, the fountain was paid for by citizens of

, who raised $25,000 by way of pennies, nickels and dimes donated by public school children. Congress also funded totaling $15,000 towards the completion.Somma, Thomas P. "The McMillan Memorial Fountain: A Short History of a Lost Monument", ''Washington History'', Vol 14, No. 2, pp. 96-107.

Sand filtration site post-closure development

References

External links

Washington Aqueduct
- U.S. Army Corps of Engineers
Pictures of the McMillan slow sand plant, with history
{{Potomac River System Reservoirs in Washington, D.C. Potomac River watershed