Salt Brine 101: A Practical Guide for Michigan Snow Contractors
By E & B Maintenance Services, Inc., Farmington Hills, MI. We have made and sprayed our own manufactured salt brine for 20 years. This guide covers how brine works, when and how much to apply, and what it costs compared with rock salt. All application rates are starting points taken from the public agency sources linked in each section. Adjust them for your own sites.
What Is Salt Brine?
Salt brine is sodium chloride (NaCl) dissolved in water. The standard de-icing mix is a 23.3% solution, the concentration with the lowest freezing point. TxDOT's snow and ice manual lists that point (the eutectic temperature) as -6°F at 23.3%. Mixing weaker or stronger than 23.3% raises the freezing point, so a tested, consistent concentration matters (FHWA Manual of Practice for an Effective Anti-Icing Program).
A freezing point of -6°F does not mean plain brine works that cold. Several agencies advise against using plain salt brine at pavement temperatures below about 15°F; see When and How to Apply.
Anti-Icing vs. Deicing
Anti-icing means applying brine before a storm to stop snow and ice from bonding to the pavement. Plowing then scrapes the surface clean instead of leaving packed snow. Deicing means applying material after snow or ice has already bonded, to break it loose. The Minnesota Pollution Control Agency sums it up: anti-icing prevents the bond, deicers melt snow and ice, and anti-icing chemicals must go down before snowfall.
The McHenry County, IL parking lot manual (adapted from Minnesota's) reports that anti-icing can provide safety with about one quarter of the material and one tenth of the overall cost of deicing after the fact (McHenry County manual).
When and How to Apply Salt Brine
Watch pavement temperature, not air temperature
Agency guidance is based on pavement temperature and its trend (MoDOT Operator's Guide for Anti-Icing). An infrared pavement thermometer, truck-mounted or handheld, is the most useful tool you can buy.
- Lowest working temperature: the FHWA manual, MPCA, and Ohio LTAP all say plain salt brine is not effective or cost-effective below about 15°F pavement temperature (FHWA, MPCA deicer fact sheet, Ohio LTAP). SIMA's sidewalk guidance recommends blending in calcium chloride for colder pavement (SIMA, Begin With Brine).
- Freezing rain: do not anti-ice before rain or significant freezing rain, because it washes the brine away (McHenry County manual).
- Timing: apply before precipitation starts. Pretreatment can stay effective for several days if it isn't washed off, and you shouldn't reapply while residue is still visible (McHenry County manual).
- Don't over-apply: rates that are too high can make pavement slippery and cause tracking (MPCA).
Road and lot rates: gallons per lane-mile
| Source | Condition | Rate (gal/lane-mile) |
|---|---|---|
| TxDOT | General anti-icing | 30–60 |
| MoDOT | Pretreatment of dry pavement before an event | 44 |
| MoDOT | Frost/refreeze, pavement 28–32°F | 11–28 |
| MoDOT | Frost/refreeze, pavement 20–28°F | 28–57 |
| Ohio LTAP | Anti-icing before black ice | 20–40 |
MoDOT also publishes equivalents between dry salt and brine. For example, 100 lb/lane-mile of solid salt is about 44 gal/lane-mile of 23% brine (MoDOT Table 133.5.3.2). MoDOT says not to apply brine at its listed rates once pavement drops below 20°F. Ohio LTAP says not to apply liquid anti-icing below 20°F, and to reapply every two hours during snowfall. For more detail on blends, see Clear Roads' Application Rate Guidance for Salt Brine Blends.
Parking lots and sidewalks: gallons per 1,000 sq ft
| Source | Condition | Rate (gal/1,000 sq ft) |
|---|---|---|
| MPCA | Regularly scheduled application | 0.3–0.6 |
| MPCA | Before frost or black ice | 0.3–0.6 |
| MPCA | Before light or moderate snow | 0.3–0.8 |
| UW–Green Bay / Dane County | Frost/sleet; black ice or light snow; moderate–heavy snow | 0.3; 0.5; 0.6 |
| SIMA (sidewalks) | Pretreat at 30°F / at 16°F pavement | 0.5 / 1.5 |
To size a job, multiply the lot area in square feet by the rate, then divide by 1,000. For example, a 100,000 sq ft lot at 0.5 gal/1,000 sq ft needs 50 gallons.
Equipment and Sprayers
Brine goes on through a tank-and-pump sprayer with a boom or stream nozzles. TxDOT applies it with stream nozzles similar to those used for other liquid anti-icers (TxDOT). Contractors commonly use skid or slide-in units from brands such as VSI, Camion, SnowEx and SaltDogg. For bonded ice and hardpack, SIMA notes that deicing with brine takes much higher rates and high-pressure nozzles that can penetrate hardpack (SIMA).
Clean product matters most for sprayers. Impurities clog fan nozzles and coat tanks, which is the most common reason operators give up on liquids. Our brine is pure enough that after a quick rinse with a garden hose, we use the same spray trucks to water landscapes in spring.
Storage and Handling
- Store brine in poly tanks or 275-gallon totes. Leftover brine can stay in your truck's tank between storms, so there are no half loads.
- Keep a fixed 23.3% concentration. Dilution from rain or meltwater raises the freezing point and can lead to refreeze (FHWA).
- Calibrate your sprayer each season so the gallons you meter match the rate you planned.
- Rinse pumps, lines and nozzles with fresh water at the end of the season.
Manufactured Brine vs. Well Brine vs. Calcium Chloride
| Manufactured NaCl brine | Well brine | Liquid calcium chloride | |
|---|---|---|---|
| What it is | Salt dissolved in water at a plant and tested to 23.3% | Natural brine pumped from Michigan Basin rock formations | Manufactured CaCl2 solution |
| Consistency | Same salinity every load | Unknown salinity; contents vary by well | Consistent from reputable suppliers |
| Impurities | None (E&B product) | Can contain other chemicals that clog nozzles and coat tanks | Depends on the supplier |
| Cold performance | Not recommended below about 15°F pavement (FHWA) | Varies | Lower eutectic point than NaCl; used for colder pavement and in blends (FHWA, SIMA) |
| Best use | Anti-icing lots, walks and roads | Mostly dust control | Cold-weather blends and pre-wetting |
The FHWA manual notes that NaCl and CaCl2 brines freeze in about the same way between 32°F and about 15°F. Calcium chloride's lower eutectic point therefore matters mainly when it's colder than that (FHWA).
Cost Comparison: Brine vs. Rock Salt
| Item | Cost |
|---|---|
| Rock salt, per ton | $150 |
| E&B salt brine, per gallon | $0.45 |
| Brine equal to one ton of salt (80–120 gal) | $36–$54 |
| Savings per ton-equivalent | $96–$114 (64%–76%) |
Application rates vary by operator. In our experience, crews that salt heavy also spray heavy. Brine also keeps your costs steadier when salt prices climb mid-season.
Environmental Notes
Chloride from road salt does not break down, and too much of it harms lakes, streams and groundwater. MPCA's guidance is to use the least material that keeps surfaces safe and to match the product to pavement temperature (MPCA deicer fact sheet). Anti-icing with brine puts down far less salt than reactive rock salting (see the McHenry County figures above). It also causes no salt burn on lawns and landscapes, and it doesn't leave rock salt residue or grit to track indoors.
Salt Brine FAQ
What concentration should salt brine be?
23.3% sodium chloride, the concentration with the lowest freezing point, -6°F (TxDOT).
How cold is too cold for salt brine?
FHWA, MPCA and Ohio LTAP advise against plain salt brine below about 15°F pavement temperature. Use a calcium chloride blend for colder conditions.
How much brine do I need for a parking lot?
MPCA suggests starting at 0.3–0.8 gallons per 1,000 sq ft, depending on conditions. A 100,000 sq ft lot at 0.5 gal/1,000 sq ft needs 50 gallons.
Should I apply brine before freezing rain?
No. Rain and significant freezing rain wash anti-icing liquids away (McHenry County manual).
How long does pretreatment last?
If precipitation doesn't wash it off, it can stay effective for several days. Don't reapply while residue is still visible (McHenry County manual).
Where can I buy salt brine in Metro Detroit?
E&B Maintenance sells 23.3% manufactured brine at $0.45 per gallon or $250 per 275-gallon tote. Pickup is in Farmington Hills, 24/7 during storms, and we deliver within 20 miles.
Buy Salt Brine in Metro Detroit
E & B Maintenance makes 23.3% manufactured sodium chloride brine at our Farmington Hills facility, near 10 Mile and Grand River. Buy it by the gallon for $0.45 or in 275-gallon totes for $250. Pickup runs 24 hours a day, 7 days a week during storms and 8am–4pm Monday–Friday. We deliver by tanker within 20 miles, including Detroit.