Verified license

Cosden Water Supply Co Inc

Randallstown, MD · Baltimore CountyWater treatment

Call (410) 922-2900
Directions
License status
Active
checked September 30, 2026
License number
WCI085
Maryland record
Services
1
Water Treatment

About Cosden Water Supply Co Inc

Cosden Water Supply Co Inc is a water treatment contractor based in Randallstown, MD (Baltimore County). The Maryland licensing program lists license WCI085 as active, and we last checked the record on September 30, 2026.

The state record covers water treatment.

This profile is built from public state license records checked on September 30, 2026. Well Water Insider does not rate or endorse contractors. Own this business? Claim the profile to add photos, hours and a description.

License record

Verified against state records
License number
WCI085
License type
Water treatment
Status
Active
Expires
June 1, 2027
Last verified
September 30, 2026

Check this license yourself on the official Maryland lookup.

What the state record says

Maryland licensed water conditioner installer (State Board of Well Drillers license WCI085, held by William D Cosden III, current through June 2027 2027 on the Board's roster of active licensees). Maryland licenses the individual under Title 13 of the Environment Article and COMAR 26.05; a master well driller may construct, repair and abandon water wells (the water supply specialization is limited to water wells, the general one includes geothermal and other wells) and install pumps, a pump installer may install and repair pumps and pitless units, and a water conditioner installer may install treatment equipment. Wells themselves need a county health department permit under COMAR 26.04.04.

Services

What the Maryland record says Cosden Water Supply Co Inc is licensed or registered to do.

Water Treatment

Sizing and installing softeners, iron filters, UV and reverse osmosis based on a lab test.

Service area

Based in Baltimore County, Maryland.

Approximate location (Baltimore County)

Well water in Baltimore County

Useful context before you call a contractor here.

16%of households in Baltimore County drink from a private well (est.)
Not statewidewater test when a home with a well is sold: no statewide rule in Maryland, but some local areas require one
Open the Baltimore County well guide

Typical costs for these services

National ranges to help you read a quote. They are not prices from Cosden Water Supply Co Inc; ask for a written estimate.

One treatment unit$700 to $3,500softener, iron filter or UV, installed
Multi-stage whole-house treatment$2,500 to $10,000+several units or whole-house RO, installed

National 2026 ranges. Sources, checked September 2026: HomeGuide cost guides, Angi.

Certified labs nearby

Test your water before and after any work on the well.

Home Land Labs – TowsonTowson, MD · 2.9 miCaliber Analytical Services, LLCTowson, MD · 3.4 miMicrobac Laboratories, Inc – BaltimoreBaltimore, MD · 8.4 mi
All labs near here

Before you hire

  1. 1

    Confirm the license

    Look up license WCI085 on the Maryland state lookup and make sure it is active for the work you need. Open the Maryland lookup.

  2. 2

    Get a written estimate

    Ask for the scope, parts, depth or pump size, permit fees and warranty in writing. Compare two or three quotes for big jobs.

  3. 3

    Ask about permits and the well log

    New wells and many repairs are reported to the state. Ask who files the paperwork and for a copy of the well log.

  4. 4

    Test the water after the work

    Any work on a well can disturb bacteria. Test for coliform bacteria once the job is done.

Questions about Cosden Water Supply Co Inc

Is Cosden Water Supply Co Inc licensed?

Yes. The Maryland record shows license WCI085 (water treatment) with the status "active", last checked on September 30, 2026. You can confirm it on the state lookup.

What services does Cosden Water Supply Co Inc offer?

The state record lists water treatment. Call to confirm they take on your type of job.

What areas does Cosden Water Supply Co Inc serve?

The business is based in Baltimore County (Randallstown, MD).

How do I contact Cosden Water Supply Co Inc?

Call (410) 922-2900. The address on the state record is 3433 Chapman Rd, Randallstown, MD 21133.

Other licensed contractors near Randallstown

Carroll Water LLC

Verified license

Cockeysville, MD · Baltimore County

License MWD553, JWD417, PI0074, WCI050 Active

  • Pump Installation
  • Pump Repair
  • Water Treatment
  • Well Abandonment
  • Well Drilling
  • Well Repair