When farm runoff and other pollutants are not controlled, as in this Loudoun County farm in 1998, bad things can happen to nearby water sources. (LARRY KOBELKA/For The Washington Post)

The report on Loudoun’s plumbing has been in the works since 2007, when a task force began looking at what parts of the county were hooked up to Loudoun Water, which parts had their own private systems, and who still had working outhouses. The answer to that last question is that there are “31 known privies still in use in Loudoun County,” and they are frowned upon for lack of sanitation and, well, everything really. A map of the active privies indicates they’re almost all west of Route 15, but you can go here if you want the report and its full details.

Loudoun’s supervisors now have some serious thinking to do. The task force report came up with dollar estimates for each of the 16 communities with problems and the 20 with suspected problems, and found that fixing them would cost more than $27 million. In addition, the report determined that as of 2009, 15,141 private drinking water wells were known to exist in the county, and EPA regulations do not apply to those wells for monitoring their quality or their ability to contaminate surrounding land, aquifers or groundwater. So good luck to those people and their neighbors.

Adding to the possible headaches: there are nearly 15,000 onsite sewage systems in Loudoun, the report found, and more than 5,600 of those are more than 30 years old. That’s not thought to be a good thing.

Here are some of the specific areas of concern in the report:

Broad Run Farms, north of Route 7, with 425 properties served by onsite water, or wells, and there is a nearby Hidden Lane Landfill. The report says that “numerous wells adjacent to the Hidden Lane Landfill are contaminated with trichloroethylene. This area is now an active Environmental Protection Agency Superfund site.”

Potomac Farms, 156 homes on Smith Circle just west of the Loudoun County Parkway. About half of those homes are served by a private water system, the report states, and the state health department has received complaints about low water pressure and “aesthetic water quality issues” (i.e. it tastes bad, looks bad or smells bad). It would take $3.9 million to replace the private system, the report states.

Hillsboro, a small town along the western part of Route 9, has 48 habitable structures served by onsite sewer and water. “The Town has been on a Boil Water Notice since 2000 (!!), meaning the water is not safe to consume unless it is boiled first.” Fixing that: $2.4 million.

Paeonian Springs, near the intersection of Route 7 and Route 9, has 116 structures served by onsite water and sewer facilities. The report rated the service there to be 13 percent unsatisfactory and 27 percent “unknown.” Cost for satisfactory water and sewer: $4.57 million.

Raspberry Falls, with 132 homes north of Leesburg on Route 15, was found recently by the Virginia Department of Health to have a public well with “groundwater under the direct influence of surface water.”

Areas not surveyed, but thought to be problematic, include the Dulles Industrial Park, Beaver Meadow Road and Tall Oaks, all in the newer part of the county.

The Loudoun Times-Mirror reported Saturday that the county supervisors were “expected to delve deep into this report this fall.” This did not occasion an outpouring of support for the county board among the Times-Mirror’s online commenters, to put it mildly.