Sec. 22-124. Percolation tests
Codified through Bill No. CB-018-2026, adopted May 12, 2026, effective July 24, 2026. Source: Municode, Supplement 2026 Update 2. Editorial notes and legislative history omitted.
Prince George's County, Md., Code § 22-124 (2026)
Sec. 22-124. Percolation testsLinkCopy Citation
(a)
A completed application or form provided by the Health Department for percolation tests must be filed with the Health Department specifying the following information:
(1)
Owner's name, address, and telephone number;
(2)
Applicant's name, address, and telephone number;
(3)
Proposed use of the building;
(4)
Number of people to be served by this building;
(5)
Square footage of proposed building;
(6)
Residential use: number of bedrooms, basement plumbing anticipated;
(7)
Commercial use:
(A)
Fixture count by type and number;
(B)
Type of operation;
(C)
Number of employees;
(D)
Type of waste expected to be discharged;
(8)
Other pertinent information as may be necessary.
(b)
A proposed site plan must accompany any commercial application specifying the proposed building site, property lines, proposed parking lot, and two (2) foot contours.
(c)
A site plan may be required for subdivisions showing the house locations, proposed wells (if applicable), five (5) foot contours, and property lines for each lot.
(d)
On lots where the Prince George's County Soil Survey maps or soil borings indicate severe limitations based on seasonally perched, seasonally high water tables, or flood hazards, soil percolation tests and any other tests, as may be required, shall be performed from February 1 - April 30 when the highest water table can be expected at the on-site sewage disposal site. The time period can be expanded or restricted by the Health Officer depending on the static water levels observed in water table wells located throughout the County. If the Health Officer or a professional soil scientist certified by the American Registry of Certified Professionals in Agronomy, Crops, or Soils (ARCPACS) finds that the soil conditions found at the on-site sewage disposal site are contrary to the County Soil Survey and that seasonably high water tables, perched water tables or flood hazards do not exist, the percolation test may be conducted at any time.
(e)
Property Identification and Water Table Observation Hole.
(1)
The applicant shall locate the property lines and proposed building on the site.
(2)
A water table observation hole shall be required from which the static groundwater level shall be determined after a twenty-four (24) hour observation period. The hole shall be located within the proposed recovery area. Subsequent percolation tests shall be conducted in the absorptive layers a minimum distance (buffer) above the determined groundwater table as determined in Table 1 of Appendix B (Section 22-152).
(3)
The Health Department is responsible for approving the proposed location of all percolation tests and water table observation holes.
(f)
Shallow Test Procedures (less than five (5) feet).
(1)
Dig or bore a minimum of four (4) test holes with a diameter from four (4) inches to twenty-four (24) inches and vertical sides to the depth of the proposed absorption trench.
(2)
Preparation of test holes.
(A)
Remove any smeared soil surfaces and provide a natural soil interface into which water may percolate. Remove all loose material from the hole. Add two (2) inches of coarse sand or fine gravel to protect the bottom from scouring and sediment.
(3)
Prewetting and test measurement.
(A)
Fill the hole with clean water so that the water level is approximately six (6) inches over the gravel. Measure the drop every thirty (30) minutes, readjusting the water level to six (6) inches above the gravel for two (2) hours. The last measurement observed will determine the percolation rate and shall be recorded as the time in minutes for the water to drop one (1) inch. If the water level in the hole fails to drop the minimum amount in Table 2 (Section 22-153) within a thirty (30) minute period, the hole is unsatisfactory. A more extensive prewet may be required in clayey soils.
(B)
Minimum requirement.
(i)
A test shall be satisfactory when the percolation rate is demonstrated to be at least .2077 gallons per square foot which is equivalent to the required minimum Maryland State Standard percolation rate of one (1) inch in thirty (30) minutes, based on a one (1) foot square test hole. Percolation rates for round percolation test holes can be found in Table 2. (Section 22-153).
(C)
In soils in which the first six (6) inches of water seeps away in less than thirty (30) minutes, the time interval between measurements shall be ten (10) minutes for a maximum of forty (40) minutes. The drop that occurs during the final ten (10) minutes is used to calculate the percolation rate.
(g)
Deep Testing Procedures (five (5) feet or greater).
(1)
Number and location of tests.
(A)
Test holes eight (8) inches to twenty-four (24) inches in diameter shall be bored to a depth where absorptive soil conditions are observed. A minimum of two (2) satisfactory tests shall be conducted to establish adequate disposal area. If deemed necessary, additional tests, or soil borings may be called for.
(2)
Prewetting and Percolation Rate Measurement.
(A)
Procedures.
(i)
The test boring shall be filled with a minimum of four (4) feet of water at which time the water level is allowed to drop a prescribed amount of inches as specified in Table 3 (Section 22-154). After the water level has dropped the prescribed number of inches, the water level is adjusted back to its original level and the procedure is repeated. A more extensive prewet may be required at the discretion of the Health Officer. The last measurement observed will determine the percolation rate and shall be recorded as the time in minutes for the water to drop one (1) inch. If the water level within any of the holes fails to drop the prescribed amount of inches within a thirty (30) minute time period, the hole is considered unsatisfactory.
(B)
Minimum requirement.
(i)
A test shall be satisfactory when the percolation rate is demonstrated to be at least .2077 gallons per square foot which is equivalent to the required minimum Maryland State Standard percolation rate of one (1) inch in thirty (30) minutes, based on a one (1) foot square test hole. Percolation rates for round percolation test holes can be found in Table 3 (Section 22-154).
(h)
Supplementary percolation tests may be required by the Health Officer if needed.
(i)
Grading and filling of the sewage disposal area may negate the percolation test. Grading and filling of the proposed sewage disposal and recovery area will not be permitted.
(j)
Supplementary percolation tests may be required by the Health Officer after three (3) years from the date of testing, or if the percolation test requirements under which they were conducted are changed by new regulations.
(k)
Once a proposed sewage disposal area has proven to be unsatisfactory due to unsatisfactory soil percolation rates, that area may not be retested at the same depth. Unsatisfactory water tables and percolation tests may not be included in the proposed recovery area.