Clean Water Act discharge permit · NPDES MDG492282

MOUNTAIN MATERIALS, INC., Joppa, MD: NPDES MDG492282 discharge permit, effluent exceedances, inspections, penalties

Administratively continuedPermit status
MinorDischarger class
5Pollutants under a numeric limit
5Pollutants with an effluent exceedance

MOUNTAIN MATERIALS, INC., held by Mountain Properties, Inc, holds NPDES permit MDG492282, which discharges to Lower Winters Run. EPA’s file records it issued December 1, 2011 and expiring April 30, 2015. The status and dates are as EPA’s permit file stood when Velarion loaded it (October 14, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.

Identity

Facility as filed	MOUNTAIN MATERIALS, INC.
Permittee as filed	Mountain Properties, Inc
NPDES ID	MDG492282
Permit status	Administratively continued (past its expiration date and still in force until reissued)
Permit type	Coverage under a general permit
Discharger class	Minor discharger
Facility type	Not a publicly owned treatment works
Issued	December 1, 2011
Expiration date	April 30, 2015
Issuing agency	Maryland Department of The Environment
Address	Joppa, MD 21085
Receiving water	Lower Winters Run
Receiving water impaired	303(D) Listed
Subwatershed	Lower Winters Run (HUC 020600030102)
SIC	1442 – Construction Sand And Gravel

Cited to the EPA ICIS-NPDES permit file (ECHO download) and EPA’s NAICS/SIC and component files, the same download.

Effluent limits and exceedances

6Pollutants on file
5Under a numeric limit
6With a violation of any kind
5With an effluent exceedance

An effluent exceedance is a discharge monitoring report value over the permit’s numeric limit (EPA’s violation code E90). A violation of any kind also counts a report not filed. Each row is EPA’s own count for that pollutant.

Pollutant or measure	Limits	Violations, any kind	Effluent exceedances	Latest exceedance	Largest exceedance, as filed
pH	4	117	20	December 31, 2024
Solids, total suspended	4	112	15	March 31, 2024	199% over the limit
pH change [range]	4	112	8	August 31, 2018
Solids, settleable	2	43	8	February 28, 2017	19,900% over the limit
Temp. difference, summer [deg. F]	0	3	3	September 30, 2025	2,147,483,650% over the limit
Flow, in conduit or thru treatment plant	4	106	0

Cited to the EPA ICIS-NPDES limits and effluent violations files (ECHO download); up to 60 rows shown, most exceedances first.

Inspections, violations and enforcement

0Single-event violations

EPA’s single-event violation file, as loaded, holds no violation for NPDES MDG492282.

Velarion’s copy of EPA’s ICIS-NPDES files does not include the inspections, formal enforcement actions and informal enforcement actions files, so this page shows none of them. EPA’s free Detailed Facility Report on ECHO lists this permit’s inspections, enforcement actions and penalties.

Cited to the EPA ICIS-NPDES violation, inspection and enforcement files (ECHO download); up to 50 rows of each shown, newest first.

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EPA publishes a free Detailed Facility Report for every permit on ECHO: its compliance status quarter by quarter, its inspections, and its enforcement actions and penalties. EPA also sends free notices of new inspections and enforcement actions through ECHO Notify; enter NPDES ID MDG492282 there.

Nearby on the register

Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.

This public-records page covers Clean Water Act NPDES permit MDG492282 for MOUNTAIN MATERIALS, INC. in Joppa, MD, held by Mountain Properties, Inc., which discharges to Lower Winters Run in HUC 020600030102. The permit is listed as administratively continued, a minor discharger class, with 5 pollutants under a numeric limit and 5 pollutants with an effluent exceedance. The permit was issued December 1, 2011 and expired April 30, 2015.