How the desk works

Every number on Sonny the Plumber comes from a published document by a utility, a government agency or an appliance maker, and every chart is drawn from those published figures alone.

Updated 6 November 2026

This note sets out where the desk's numbers come from, how they become charts, and where the record has gaps. It applies to every page on the site, from the front page to the shelves on your bill, your water, your pipes and your heater.

Scope of the desk

The desk covers the water and plumbing side of a house in Clarksville and the rest of Montgomery County, Tennessee: what the bills charge, what is in the tap water, how cold and wet the year gets, how high the rivers run, and the rules for permits and septic systems. It does not visit houses, test water, or rate contractors.

Where the money figures come from

Water, sewer and gas charges come from Clarksville Gas & Water's own rate documents on the city website: the water and sewer rate schedule, whose last published step took effect July 1, 2024, and the gas rate sheet effective October 9, 2026. CGW's gas commodity charge moves about monthly, so any gas figure carries its date.

Electric figures come from the two power companies that serve the area. CDE Lightband (Clarksville Department of Electricity) publishes its residential rates and fees; Cumberland Electric Membership Corporation (CEMC) publishes a rate sheet each month. Neither publishes the exact line between their territories, so the pages say to check which utility bills you. Statewide averages come from the U.S. Energy Information Administration, and the heat pump water heater discount from TVA EnergyRight.

Where the water and house figures come from

Tap water: CGW's annual drinking water quality report for 2025, and CGW's public lead service line map, which we counted ourselves.
Weather: NOAA NCEI's 1991–2020 climate normals for the Clarksville WWTP station, USC00401790. It has a full 30-year record; the Outlaw Field airport station, with a shorter record, appears only as a cross-check.
Rivers: National Weather Service gauges CKVT1 (Cumberland River at Clarksville) and PORT1 (Red River near Port Royal), plus USGS streamflow statistics.
Ground: USGS geologic maps and karst reports.
Use and leaks: EPA WaterSense.
Heaters and safety: ENERGY STAR, the Consumer Product Safety Commission, and the installation and care manuals that A. O. Smith and Rheem publish for their electric tank heaters.
Rules: TDEC (septic, wells, sinkholes), the Tennessee Board for Licensing Contractors, City of Clarksville Building & Codes, and Montgomery County Building & Codes.

How the charts are drawn

Charts use only numbers printed in those documents. We do not estimate, smooth or fill gaps. When a chart or sentence needs a step beyond the source, such as multiplying a leak volume by a rate or turning months into weeks, the step is labeled "our arithmetic" in the chart note or the sentence beside it. Each chart names its source, links to it, and says in one line how to read it.

Rates are shown as published, before taxes, with the date they took effect. Where a source gives no effective date, as with Montgomery County's permit fees and TDEC's septic fees, the page says so rather than guessing one.

Dates checked

Every source on the site was checked on 6 November 2026. A figure that changes often also carries the date it took effect. When a utility publishes a new rate step or a new water report, the affected pages need a fresh check; until then, the numbers stand as of that date.

What we could not check

Some state and federal pages would not load for us. Several tn.gov pages, including licensing, septic and emergency-management pages, answered with access blocks, and the Department of Energy's Energy Saver pages returned errors. For those we used copies held by the Internet Archive's Wayback Machine. Every archived copy is labeled on the page as an "archived copy" with its capture date, and the link goes to that copy, not the live page.

A few gaps remain open. Some figures we found only in scanned documents without readable text, and we left those numbers out. Where a source disagrees with itself, as A. O. Smith's manual does on how often to have the relief valve inspected, the page quotes the instruction that sends you back to your own manual. Each page ends with a short note on its own gaps.

Errors and corrections

Corrections cannot be sent through this site: it has no form, no email address and no comment box. If a figure here looks wrong, rely on the source document linked beside it, which is the authority in every case. Utility rates, permit rules and fees change, and the issuing office has the final word.

What the desk is not

The desk is not a plumber or a contractor and does not recommend firms. Safety notes on the pages follow the utility, agency and maker guidance cited, and where work needs a license or a permit, the pages say so. More about the site is on the about page.

Sources

Clarksville Gas & Water — Water Rate Schedule A · water and sewer rates, last step effective July 1, 2024 · checked 6 Nov 2026
Clarksville Gas & Water — Gas Rates effective October 9, 2026 · residential gas charges · checked 6 Nov 2026
Clarksville Gas & Water — Annual Drinking Water Quality Report 2025 · hardness, lead, copper and other results · checked 6 Nov 2026
CDE Lightband — Rates & Fees · residential electric rates · checked 6 Nov 2026
CEMC — Rates effective October 1, 2026 · residential electric rates and fuel charge · checked 6 Nov 2026
TVA EnergyRight — Heat Pump Water Heater · discount terms · checked 6 Nov 2026
U.S. EIA — Electric Power Monthly, Table 5.6.A · Tennessee average residential price · checked 6 Nov 2026
NOAA NCEI — 1991–2020 normals, USC00401790 · freeze nights, rainfall, degree days · checked 6 Nov 2026
NOAA NWS — Cumberland River at Clarksville (CKVT1) · flood categories and crests; Red River PORT1 from the same service · checked 6 Nov 2026
USGS — Hardness of Water · hardness scale · checked 6 Nov 2026
EPA WaterSense — Fix a Leak Week · household leak figures · checked 6 Nov 2026
ENERGY STAR — Heat Pump Water Heaters, Benefits & Savings · savings by household size · checked 6 Nov 2026
CPSC — Avoiding Tap Water Scalds · burn times by temperature · checked 6 Nov 2026
A. O. Smith — Residential Electric Water Heater Use & Care Guide · flushing and relief-valve steps · checked 6 Nov 2026
Rheem — Electric Residential Water Heater manual · relief-valve test · checked 6 Nov 2026
TDEC — Septic System Construction Permit · septic fees; archived copy of 31 Aug 2026 · checked 6 Nov 2026
TN Board for Licensing Contractors — Contractor license · license threshold; archived copy of 14 Apr 2026 · checked 6 Nov 2026
Montgomery County Building & Codes — Building Permit Fees · county permit fees · checked 6 Nov 2026
City of Clarksville Building & Codes — Permitting · city permit rules · checked 6 Nov 2026